Your comments

I have been able to solve/reproduce the problem by exchaging an office router with a different model. I haven't been able yet to see a difference in the HTTP GET that would cause the 403. *shrug*

Seems to be a local network issue, investigating further - please ignore for the time being.

wireshark reports:

GET / HTTP/1.1

Icy-Metadata: 1

User-Agent: Dalvik/1.6.0 (Linux; U; Android 4.2.2; Nexus 4 Build/JDQ39)


Connection: Keep-Alive

Accept-Encoding: gzip

ICY 403 Service Forbidden

icy-notice1:<BR>SHOUTcast Distributed Network Audio Server/Linux v1.9.8<BR>

icy-notice2:The resource requested is forbidden<BR>