Sudden high latency?

[PoliticalBonobo]

New problem here; wondering if anyone has seen this.
I'll be in the middle of a project, running at 48kHz/24bit, 128 sample size just fine. At some point along the way, I suddenly get massive latency. The strange thing is that I never changed the sample size from 128. I'll notice it when playing/recording MIDI or guitar...it's unplayable. Changing the sample size does nothing.

Any ideas? This is a huge work stoppage for me.

Edit: So far, I've restarted the computer, stopped/started the MOTU audio system to no avail. When it happens, it seems to be stuck in the project, i.e. creating a new project doesn't have the latency issue. This is the second project where this has happened. I recorded guitar just fine. Did some editing, went back to record, huge latency. I didn't load plugins in between or anything...as far as I can think of, I literally did nothing between recordings.

[PoliticalBonobo]

Within the minute of posting, I found the culprit: Waves SoundShifter. I didn't realize the latency was track specific. I've had SounShifter loaded for most of the project with no issues. It appears to be very buggy within DP