Okay...
Here's what I did:
Starting out the issue presented itself 1 in 5 launches of the mythfrontend - watch live tv.
1. Modified each mythtv frontend to use the OSS devices vs the ALSA, both the Mixer (/dev/mixer) and the output (/dev/dsp)
- Impact - Issue presented itself 1 in 8 times
2. Set the pci latency from the default of 64 to 128
- Impact - Issue presented itself 1 in 16 times
3. Set the pci latency from 128 to 248 (sample syntax below)
- Impact - Issue has not yet resurfaced - tested 25 times
setpci -v -s 01:06.0 latency_timer=F8 #<-- the value must be in hex
setpci -v -s 01:06.1 latency_timer=F8
setpci -v -s 01:06.2 latency_timer=F8
setpci -v -s 01:06.4 latency_timer=F8
setpci -v -s 01:07.0 latency_timer=F8
setpci -v -s 01:07.1 latency_timer=F8
setpci -v -s 01:07.2 latency_timer=F8
setpci -v -s 01:07.4 latency_timer=F8
The wiki has been updated to include this information.
http://wiki.linuxmce.org/index.php/PcHDTV_HD5500#Troubleshooting