LP Recording - sound distortion after 14 Minutes

I have just installed the latest version of Audacity (2.0) and used it to record 4 LPs. On each side of each LP, the sounds starts to deteriorate after around 14 minutes.

These are old LPs and cheap equipment so I am not expecting brilliant quality, but these are unlistenable - crackly, and distorted (eg. Herp Albert sounds like he is playing a Kazoo rather than a trumpet).

If it wasn’t for the fact that it happens around the same place each side, I would have thought it could be interference.

Could it be a memory or buffer issue?

Thanks for any pointers!

If you start a fresh recording by playing a last track, it sounds OK?
Tell Audacity to record the built-in microphone on your laptop instead of the USB turntable. Come back in fifteen minutes. Is your voice distorted?

Koz

Thanks for the suggestion Koz - I will try that out.

So far I thought the problem may have been due to my netbook going in to powersave mode, but after some more experiments am now pretty sure that is not the problem. Will get back when I have found a fix.