Total System lockup during live show production (twice)

Question

This may be too specific but here goes. I do my podcast live every Sunday night on Ustream, and every week it runs fine. Last Sunday and this Sunday I had a complete system lock up in the middle of the show. I thought it might be temperature, but I watched it carefully this week and had two cooling mechanisms so I don't think it was that.
I run Camtwist to pipe my desktop and picture in picture from my iSight on my Cinema Display. I run Audio Hijack Pro to pipe the audio to Soundflower from my Heil mic (via a USB interface) and from GarageBand where I'm recording. Feeder is what I'm reading my shownotes from and I've got Safari running to push everything to Ustream. Finally I've got Colloquy running to participate in the live chat. I know, a lot of balls in the air for me AND my Macbook Pro, right?
MBP is running Snow Leopard and is a 2.53GHz core 2 duo with 4GB of RAM, plenty of hard disk available.
After the lockup I rebooted and pulled the console logs right away. So what should I be looking for? I can see right where it died last week (6 minute gap in the logs) and the end of the logs for this week. I don't see anything that says "your system crashed because..."
The audience has been tolerant of my disappearing act but it's gonna get old soon!
Allison Sheridan
NosillaCast Podcast at ******
A technology geek podcast with an EVER so slight Macintosh bias!
Follow me at ********
<edited by host>

Answer 1

Have to point out that you should work hard to be sure all 3rd party apps AND plug-ins are fully Snow Leopard compatible...and yes, that's quite a load for a laptop.
Try resetting some of the hardware involved (PRAM~NVRAM). See this Apple KB for details, etc.:
http://support.apple.com/kb/HT1379
Can't hurt to try, and apparently this has helped others recently.
As well, have you done due diligence on the basics.... confirm sufficient free space on the HD; validate disk health via DiskFirst Aid, never install SL from downloaded torrents/betas, etc. Let Spotlight finish indexing; clear out old cache files and outdated/broken/duplicate fonts; find and delete related plists.
And again, be aware that laptops are typically resource constrained - streaming as an example can tax the hardware and software. If you have large demands you might want to consider a desktop system.
Also, the general approach at this time is to ask if you've checked for any problematic fonts (all languages) with Apple's Font Book (look in the Applications folder). Find and remove all duplicates also.
Start there to be sure all fonts that are in play come out with a clean bill of health.
Don't hesisate to perform wholesale deletion of old and/or little used fonts - be skeptical of anything that has come from Office 2008, including those related to an Equation Editor installation.
If issues continue, you may consider walking that portable in to the nearest Apple store and asking for opinions from the staff.
Good luck in any case.