strange crashes

[worker201]

my computer has crashed twice in the last 2 hours, which is 2 times too many. First was when I attempted to download an excel file from my ftp server via Firefox. Everything just froze, even the mouse, and the only thing to do was flip the power switch.

The second time was when I was using the Adobe Reader to open a pdf file - everything froze again, but this time, the mouse still moved, and I could still hear sound.

I don't know what's going on here. I looked in /var/log/messages around the times in question, and I see a bunch of stuff like this:

Jun 27 14:40:23 holcombe2 kernel: Inbound IN=eth0 OUT= MAC=00:07:e9:e3:99:48:00:12:43:ba:b4:42:08:00 SRC=205.188.9.112 DST=128.194.106.137 LEN=1400 TOS=0x00 PREC=0x00 TTL=107 ID=14592 DF PROTO=TCP SPT=5190 DPT=45133 WINDOW=16384 RES=0x00 ACK URGP=0

That's just a sample, there are about 20 of those in a row. It seems like just a record of an internet transaction.

Can you tell me what files might provide more info?

[Tux]

With it being summer, could it be temperature?
Sorry to keep offering this as a suggestion but it's becoming a problem these days.

[worker201]

Thanks, but we have a well-conditioned office. Actually, it's a bit cold in here...