MBP suddenly goes blank, fans start flying... help?

ive had a number of issues with this thing and am finally getting things going correctly. one last problem is this...
i have 3 programs open, firefox, mail, and bittorrent. im checking websites when, out of nowhere, my screen goes blank, the backlights come on for my keyboard, and the fans start spinning at a high rate. the computer continues to do this. the only way for me to get out of it is if i manually power down (hold power button). during this whole thing im plugged into the power adapter. could it be an app that's causing this? i have ialertu (which is the only thing i can think ofr that may be doing this).

here is a list of my last system logs. if anyone has any ideas pls let me know. I believe it went down @ the 10:21 position.
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2006-08-08 10:10:13 -0500
2006-08-08 10:10:14.241 SystemUIServer[87] lang is:en
2006-08-08 10:10:15.642 iCalAlarmScheduler[123] * -[NSBundle load]: Error loading code /Library/InputManagers/Menu Extra Enabler/Menu Extra Enabler.bundle/Contents/MacOS/Menu Extra Enabler for bundle /Library/InputManagers/Menu Extra Enabler/Menu Extra Enabler.bundle, error code 2 (link edit error code 0, error number 0 ())
2006-08-08 10:10:16.244 BluetoothUIServer[131] * -[NSBundle load]: Error loading code /Library/InputManagers/Menu Extra Enabler/Menu Extra Enabler.bundle/Contents/MacOS/Menu Extra Enabler for bundle /Library/InputManagers/Menu Extra Enabler/Menu Extra Enabler.bundle, error code 2 (link edit error code 0, error number 0 ())
2006-08-08 10:10:22.348 Mail[151] * -[NSBundle load]: Error loading code /Library/InputManagers/Menu Extra Enabler/Menu Extra Enabler.bundle/Contents/MacOS/Menu Extra Enabler for bundle /Library/InputManagers/Menu Extra Enabler/Menu Extra Enabler.bundle, error code 2 (link edit error code 0, error number 0 ())
2006-08-08 10:10:29.888 BluetoothUIServer[217] * -[NSBundle load]: Error loading code /Library/InputManagers/Menu Extra Enabler/Menu Extra Enabler.bundle/Contents/MacOS/Menu Extra Enabler for bundle /Library/InputManagers/Menu Extra Enabler/Menu Extra Enabler.bundle, error code 2 (link edit error code 0, error number 0 ())
2006-08-08 10:21:31.936 System Preferences[221] * -[NSBundle load]: Error loading code /Library/InputManagers/Menu Extra Enabler/Menu Extra Enabler.bundle/Contents/MacOS/Menu Extra Enabler for bundle /Library/InputManagers/Menu Extra Enabler/Menu Extra Enabler.bundle, error code 2 (link edit error code 0, error number 0 ())
2006-08-08 10:24:17.625 Console[225] * -[NSBundle load]: Error loading code /Library/InputManagers/Menu Extra Enabler/Menu Extra Enabler.bundle/Contents/MacOS/Menu Extra Enabler for bundle /Library/InputManagers/Menu Extra Enabler/Menu Extra Enabler.bundle, error code 2 (link edit error code 0, error number 0 ())