This issue is Android related. If you are running on a Android version lower than 2.3.4, you should know that there are internal problems with the aacPlus engine of the OS. This has been fixed on Android 2.3.4 and higher. Tested by me on a rooted HTC Wildfire with Cyanogen 7 based on Android 2.3.4 and on a Dell Streak 7 tablet with Honeycomb 3.2.

BTW Jona, you should do something with the interface of the app. On my tablet the interface is really buggy and messed up.

The internal streaming engine stutters aacPlus streams. It never worked like it should. Android's streaming engine is fluid but has some continous clicks from time to time. It's more odd since on Android 2.3.4 aacPlus worked flawless and from 2.3.5 the sound randomly clicks...
I don't want to roll back to Android 2.3.4 because it's battery hungry.

Well, it looks like I'll have to live with it :)

I just flashed Cyanogen 217 nightly based on Android 2.3.7 and then Cyanogen 207 nightly based on Android 2.3.5 (wich I use now). I believe that the app needs to be optimised for this Android versions, because on aacPlus streams sometimes the sound clicks. It's not a matter of CPU because I overclocked @ 700 MHz and the issue still persists. The sound quality is incredible, nothing compared to Android 2.2 wich really sucked, but this issue needs attention. It also may be useful to know that on Cyanogen 7.1 RC1 based on Android 2.3.4 there are no issues with aacPlus streams even if the CPU is overcloked or not.

I'm back with something new on this issue. It seems that Android's CPU clocking is the main reason for this issue. I managed to turn S-OFF on HBOOT and root my phone. I installed a custom Froyo ROM. You can find it HERE . The kernel supports underclocking (i'm not a fan of overclocking). I installed OS Monitor and through that app I always set the conservative CPU mode on the phone. This allows Android to scale through 3 frequencies: 245760 - 48000 - 528000 (never from the minimum to the maximum). The phone rarely needs to run on 528 MHz. On non rooted phones, Android forces the scale (ondemand) from 48000 to 528000, even though in most cases 528 MHz is more than needed and that makes the aacPlus playback to stutter.

After rooting and using conservative mode on CPU, when I play aacPlus streams with XiiaLive minimized and the screen off, the playback is flawless with ZERO issues. I believe the issue is fixed. The only thing left for Wildfire users is to root and install a custom ROM, or live with it :)

Thanks for everything guys.
P.S. On CyanogenMod 7.03 aacPlus streams don't work, but I believe it's an issue regarding Android 2.3.3 media framework.

Well, I can hear the improvement. The playback is at about 99% of what it should be. It's flawless, very few glitches at some points but almost not noticeable. The only moment it stutters is when I turn off the screen for about one second, but I can live with that :) I've been running XiiaLive minimised for some while now. I haven't tryed to turn off the screen with XiiaLive maximized, but since I get good performance when minimized I will only use it that way. 

Also, I've noticed some improvement when the network fails and XiiaLive tryes to reconnect. It reconnects faster than v2.2.2.

Good work. Keep it up. If there's room for more improvements for the aac+ streams, make them.

I'm looking forward to purchase the PRO version when the final release is ready.

AOR stopped working with aacPlus streams on HTC Wildfire since the last update (2010). I believe they dropped the support for it. The version before the one in Android Market worked really fine with Wildfire. I will try to find a apk with that version and email it to you. I deleted it from my SD card some while ago when I discovered XiiaLive :)

My Wildfire's CPU also runs at about 7 - 11% when the screen is on. I checked with OSmonitor. Something happens when the screen is turned off. I believe that decoding of aacPlus streams needs more CPU, and since when turning off the screen something happens, xiialive stutters audio if it's not minimised before turning off the screen.

I just remembered that the playback of aacPlus streams with xiialive minimised, is similar to the old AOR software (before the last update it used to work on Wildfire.. the development has been discontinued). When AOR was used maximized, it never had this issue. It also displayed metadata (if that helps).

In conclusion, I believe something is happening with Xiialive right after turning off the screen when the app is maximized.

I've got this issue sorted out a bit. It's the best solution for now.

The best way to avoid this issue is to keep the player minimised before turning off the display. Another thing I have done is to install AND SET UP PROPERLY Advanced Task Killer Free. I ignored all the important software needed by android and placed a widget of the program on the main screen. The steps I take are the following:
1. I start XiiaLive, go to favourites and play a station.
2. I touch the screen for preventing it to turn off untill the stream plays for about 10 secs after the buffer.
3. I minimise the app and press the Advanced Task Killer widget to kill everything else that runs in the background. This does not affect the playback of XiiaLive.
4. After all these steps, I turn off the screen and the playback is 99% flawless.

If I don't minimise the app, this issue occurs as described in this topic. I believe it has something to do with retrieving the metadata. I've noticed it especially when a song ends and another one starts playing... that's when it stutters more often. It seems that even if the display is off, when the app is maximised, it uses lot of CPU. Even the battery life is better since I run XiiaLive minimised before turning off the screen.

I found the app on the market and updated it. Maybe you'll be surprised to find out that for the first time the playback of aac+ is better than ever. I never experienced such a good playback with this app. There are some times when this issue occurs, but it's not so annoying anymore.
How about the internal streaming engine? Any hope to make it work flawless on this phone in order to fix this issue for good?

I've noticed that since the last update, XiiaLive is no longer available in the Market for HTC Wildfire. Is there any particular reason for that?