[mythtv-users] live tv and recordings suffer "spurts"

[Al B]

i've searched through the lists and not found anything precisely
relevant - apologies if this is old ground.

setup:
myth 0.15.1
gentoo with kernel 2.6.7, with kernel dvb drivers
nova-t with tda10045h frontend

symptoms:

live tv playback on all channels suffers from sporadic "spurts" -
video plays back in fastforward whilst audio mutes or crackles.
returns to normal if playback is skipped back slightly, and will then
play through previous fault point without problems. will recover on
its own if allowed to FFWD for a few seconds.

recorded tv also suffers same symptoms.

backend console (whilst recording or viewing live tv) reports:

Uncorrectable error in packet, dropped.
Transport Stream Continuity Error, PID=(XXX)

whilst viewing recording various including:

Invalid mb type in (B,I)Frame at XX XX
Warning MVs not available
ac-tex damaged at XX XX
mb incr damaged

under XP using same HW and aerial, live tv has no problems.