Overdubbing errors

I've had two problems related to overdubbing on my MPC500 now since I got it.

1: I'll be performing live, and I only get a limited number of times to overdub before I can't overdub anymore. The only way to continue using the overdub function is to stop playing completely and start again. Sometimes I have to do stop/start twice in order to overdub again.

2: Usually when this starts happening, my sequences start to bleed into the following sequence. For example, I'll be on sequence 6, and when I transition into sequence 7, which has different sounds going, the sounds from 6 will come along and add themselves over the top of what's on sequence 7.

I have the MPC maxed out, I think. 2GB flash, 256 MB of RAM (Kingston brand).

Any ideas what this could be?

I haven't tried reloading the OS. Is this an easy process? I guess I could give it a try.

All my sounds are created by me via mics and soundforge...my samples are basically all mono.

Never tried restoring it. I formatted the card about a week ago, and reloaded all the sample folders. I think it helped, but just a little bit.

My MPC started "running out of steam" at about 15 minutes into my set last night, it used to happen in a shorter timeframe.

Lampdog wrote:Have you tried reloading the os?

Have you tried using mono sounds when mono is actually needed instead
of recording/sampling stereo when the sound actually contains no stereo movement..
(this cuts down on polyphony).

Have you tried restoring the unit back to default (I don't own one I'm just asking/guessing).

Have you tried purging any unused samples and programs?