One idea: Does your building experience power outages / glitches? The "legacy" parallel and serial ports on the Advanced Mini Dock (and I think Advanced Dock too) don't like to lose power, and will lock up an attached ThinkPad if AC power loss occurs. If you don't use these ports the easiest fix is use BIOS to disable them. I forget the exact name of the BIOS setting, it's something like "Legacy ports on Dock", which you want to disable. If you do use these ports, then I'd suggest plugging your dock into a UPS in order to prevent AC power loss.
Hmm...
Ordinarily I'd suspect faulty RAM, but you say it never locks up when running from battery, so that rules out RAM.
Another guess is that your computer might be overheating. One way to monitor temperatures is to install TPFanControl. There's no need to use the fan control part of it if you don't want to (set the "Mode" to "BIOS (embedded controller)" using the GUI and/or config file.) That will at least tell if you temperatures are getting really high. Factory default is to run the CPU at higher speeds when on AC and lower speed on battery, so this could explain the lockups happening only when docked. If you see high temperatures (or even if not) you could try blowing compressed air into the cooling vents on the back left side to dislodge any dust that's accumulated on the heatsink. If you still have high temperatures and/or lockups, you may be looking at sending your machine in for sevice while it's still under warranty.
Good luck!
P.S. I assumed you're using the Advanced Mini Dock (i.e. no external graphics card). True?
Whoops, I forgot -
For others who may read this: It doesn't matter whether you actually have anything plugged into the parallel or serial ports on the dock - it will lock up your computer if the dock loses AC power. So you still need to use the BIOS option to disable legacy dock ports or plug your dock into a UPS to prevent this.
It wouldn't hurt to test the RAM. From Lenovo Support you can download a CD image of PC Doctor. (Enter your machine type and then choose Downloads and Drivers). You can burn that to a CD, boot with it, and run tests on the computer's RAM and other hardware. Another excellent RAM tester is Memtest86+.
I've seen other computers (not ThinkPads) freeze because of problems with the wired network connection (ethernet card). Probably not what's going on in your case. But it definitely helps if you can identify things (hardware configuration / connections / running software) that are associated with your machine freezing.
Good luck!
Me again! Sorry -- I seem to be having an "afterthought day".
Another thing you could try is running mprime in test mode. Have it run 2 threads to stress both cores of your cpu. (I think it may do this automatically.) Running this will put your machine under maximum stress and really heat up the cpu and memory. If you can run this for 30 min - 1 hr with no errors, you can be pretty sure you don't have a cpu or memory problem. Do make sure that your fan comes on shortly after starting this so that your computer doesn't melt! Notebooks aren't really meant to have software like this running full time, but it can be quite useful for testing. You might want to make sure you have current backups before running this...
Again, good luck. I'll shut up for now :-)
