[mythtv-users] Tuner weirdness

[Clay]

My slave backend has an Avermedia A180 and Kwold ATSC115.
v0.21 on Ubuntu 9.04

Everything I've read says both cards should work off the same sourceid and tune the same frequencies.
Most of the time this is true.
On occasion, one or the other refuses to play a channel while the other receives it fine.
Tonight, the A180 shows this on KCAL 9 HD:
http://home.pacbell.net/clayt/a180kcal9hds.png
While the ATSC115 shows:
http://home.pacbell.net/clayt/atsc115kcal9hds.png
The A180 is working for other channels so the card is fine. Here is WGN:
http://home.pacbell.net/clayt/a180wgn96s.png
Other HD channels play ok on the A180. Here's HCET:
http://home.pacbell.net/clayt/a180kcet412hds.png
Time Warner transmits WGN on a couple different frequencies.
The ATSC115 gets it on 759000000 and 585000000 but the A180 will only tune it on 759000000.
The problem comes and goes. No reboots or anything, and both cards will be tuning all channels again.
Any ideas why these cards randomly malfunction?