RMA HD-PVR, replacement from Amazon, do nothing?

[limiter]

I have a D2 HD-PVR on WinXP SP3 I bought from Amazon and have had lockups, but they are not consistent. Sometimes I can record 8 hours a day on different channels or one channel and all is fine, and I sometimes I cannot record even one hour without the HD-PVR locking up (can happen at the beginning, or middle of a recording). The longest it has worked without problems was a week.

I tried:
Tape over IR Receiver.
Firewire Channel changing (instead of built-in IR).
Latest driver from Hauppauge website.
Turn off and on the HD-PVR magic property.
Made sure the device was only USB device on USB root.
Fixed cable box at 720P.
Only use analog Audio (no optical) recording.
Box is kept in cool location.
Installed latest SageTV 6.6.2.
64k Clusters (of course).

I have a HDHomeRun that works great. I used to have an analog tuner that worked great before and is now removed.

My cable box signal can get pixelated bad on some channels (Comcast says the lines should be replaced, and claim they're working on it for the last 3 years-- i have little hope this will be fixed), but it seems recordings of even the worst pixelated content with almost unwatchable video and no sound does not bother the HD-PVR.

The question is: RMA to Hauppauge and hope they give me something that is tested and works? Get an advanced replacement with free shipping both ways from Amazon and hope I get good one? Do nothing and blame Comcast/Try something else that i've missed in troubleshooting?

Thanks for any advice.

[Chriscic]

Get it replaced by Amazon, since that's free.

I had to RMA three times to Hauppauge to get my current E1, which never locks up (knock on wood) after months of pain with C1, C2, then a D2. So I doubt they test the units extensively before sending.

My second unit is a D2 and also doesn't lock-up anymore so (knock on more wood), so you don't need an E1 to get one that works.

[limiter]

Thanks for the advice. I went with Amazon for the return, they are cross-shipping overnight a new HD-PVR (for free), paying for return shipping, and wrote a very apologetic letter even though it is not their fault. It is nice to have good customer service. Hopefully I'll have better luck doing this than Hauppauge RMA.