djing with abelton live, pauses in play back

[DM1000]

Hey guys I'm a keyboardist and

I've developed this djset that I want to try using live. I use 5 tracks
track 1 for loops
track 2 for full length songs
track 3 is a a rack holding 3 drum racks each filled with samples that I can trigger during the show
track 4 is a rack consisting of 2 VST pro 53 synths
track 5 is another vst for playing bass

I've also got sends set up for real time ping pong delay and on track 1, 2 3 I've got 3 band EQ.

I'm using the clip session view and I've got about 35 scenes which equals a 35 song set I guess. Each song is loaded up in each scene.
For midi controllers I'm using the apc 40 and the mpk 61

I run the music off my external HD.

For the most part the set plays smoothly but every so often during practice, the set "hiccups" or everything gets jammed, the music stops for a coupla secs as if the cpu is overloading. There's no telling when it will do this and it doesn't happen in the same spot everytime.

Obviously I can't play this live until I am confident that the hiccups won't happen. Is there anything I can do to stop this from happening? I also was told live was rock solid as a dj performance tool so I'm kinda confused as to why the hiccups in playback.

My computer is Mac OSX 10.5 with a 2GHz intel core duo and 2 GB 667MHZ SDRAM
Soundcard I'm using is a firebox.

[bassistheplace]

Have you checked the buffer size?

[DM1000]

hmmm, no? I'll check today and see what happens. currently its at 601 samples is that too high?

[supamonsta]

I run the music off my external HD.

maybe problem could be coming from this, could you not just have your live set and samples in the internal HD?

cheers