Ok, major problem, help please

As some of you have maybe read, I'm "testing" Reaper. The last 2 sessions I've had, I'm getting output glitches/drop-outs. Never had this, even with a ton of tracks, with Reaper so far. The time display area of the the transport bar lights up in a "block" of red, and playback gets a very short "blip" (sound cuts out entirely). What's going on? What does the "red" mean? This wasn't happening a couple days ago, and it seems to be completely random, and ONLY output-based, as tracking (yes, it's happened during tracking, but they don't end up in the recording). Ideas? Disk-read thang?

Are you using lots of plug-ins in mixing this time? They can be very CPU hungry. If so, try increasing your latencies during mixdown.

Disk space is low. Plugins are not heavy at all. CPU is low. I do not have this behavior with Cubase SX3. Does anyone know what the "red" time display actually means?

I had something like this that was stopped by changing the disk buffer read type in buffering preferences. Might be cos i have raid and something is going "squiffy" ;)

Dude - 5400 RPMs is slow for an audio drive, and top it off by not having any free space on the drive & it's not surprising you're having issues. Windows does not behave well when the free space gets below 5%. if I were you, I'd find a way to clear out some space in the short term, and plan on upgrading to a faster drive in the longer term.

Get an external USB hard drive that is 7200 rpm. It is best to have a separate drive for recordings.