For the record, I installed FC5 last night and Flash audio did not
seem to work for me either. /dev/dsp was there, the ALSA OSS
compatiblity modules were loaded, and XMMS using the OSS output plugin
worked fine. My default soundcard is a Delta 66, but my motherboard
has on-board audio. It turns out Flash audio is going to the
motherboard audio while everything else is coming out the Delta 66
(including XMMS using OSS).
Strange...I guess I should disable the on-board audio in the BIOS, or
at least fiddle /etc/modules.conf...