Audio cuts out at mid-CPU.

I'm working on a project, and the CPU is at roughly 38%, which isn't low but not very high. It might not be the CPU causing it, but I haven't added any different plugins to what I already had when it was working fine. I even bounced some tracks out to see if it was CPU! I'm really enjoying Reaper, so I hope this can be fixed! Thanks. (:

more details on your sound device n pc would help. if audio cuts in and out at points on playback it often means a windows or other task is... interfering with the recording process. this can happen if your recording to the same drive as the win os resides on. another possibility is the sound device shareing a bus..eg pci with another device. whether this is your case i dont know. more details on your problem would help.. a more fuller description. does this happen with a few traks ?? if it doesnt it might be a drive bottleneck. its very difficuult to comment without more details on your pc as well as knowing what trak counts the problem occurs.

I'm on Mac OSX, so it could just be something to do with Reaper Mac Beta or something. I'm not recording anything. This is the first track I've done in Reaper, I can't comment on whether it's only this track. It seems to work if I solo the drums, and the bass separately, but playing them together is a no-no. The bass channel is clean, and the drum channel is a bus with a Reaper EQ and Reaper Compressor on it. My MacBook is the late 2008 Aluminum version (Now discontinued) and has 2Mb of RAM and a 2GHz dual-core processor. The problem only just started today when I was working on the track. Hope that clears up a few things. :D

Found out it was the limiter on the master. The native Reaper one I think. It was cutting the audio off every time it went over 0.1dB. Panic over! :D