Since Yvan has brought this back up to the top again, I'll throw my 2 cents in.
I used to get kernel panics frequently with 10.0.x, but they got rid of most of them when they went to 10.1. Kernel panics occur only when there are serious bugs in code being run as part of the kernel or when there are significant hardware faults. So, since serious hardware faults are rare, mostly this means bugs in the kernel and certain low-level drivers, such as disc, graphics, I/O, and network drivers. There probably are still some flaws in the main kernel, but not much. It has been fairly extensively tested on most computer models and I think that about all of them have been found. It's most likely to be a flaw in one of your low-level drivers. If you have any drivers which you have installed for low-level hardware components (you probably don't have to worry about drivers for printers, scanners, monitors, or input devices like keyboards, mice, or joysticks), then check to see if there is a newer version of them available. If they happen quite frequently, you probably need to try uninstalling drivers and/or hardware to see what the problem is. If it happens very infrequently, I wouldn't worry about it too much. It will likely be fixed by some future update to the driver software.
That's the general information. Here's my specific guess: you said that you were getting on-line. This invokes kernel code to create a new network interface. This is most likely to be the problem. I have no idea how you get on-line, whether it's through modem or wired broadband or WiFi or what, but that's most likely where your driver problem is. If you're not using any third-party or non-standard drivers, then you probably can't do a thing about it. If you are, you can try reinstalling them, although that may or may not improve things. They may just be buggy. I know mine is. I use the freeware wireless driver (
http://wirelessdriver.sourceforge.net/), and although it's better than nothing, using it is fraught with peril of kernel panic. I get about one a week. It's always when putting in or taking out the PC-card or if I leave it in when I put the computer to sleep and then wake it again. I know how to reproduce it pretty well, though, so I might try to fix it when I have some time this summer.
Keith
