Well ive never had a reboot while running transmission but i've had reboot doing random things. While im not certain your reboot was random, its possible. I hope your device is otherwise stable? Also, backlight makes no difference for me, dl keeps going... but you can force backlight on when on ac in control panel.

A continuous 600kb download huh... i wonder from how many sources. Yes that would pretty much run cpu pegged at 100%, wifi adapter at 100%, and sd i/o fairly heavy... one would hope designers stress tested such a scenario, but you may be uncharted testing territory :S

My recommendation while you determine stable settings is to put caps on peers and throughput. Author has done that to some extent in 1.02 but i think he removed them from preferences screen (meaning you'd have to edit the config file yourself in /home/user/.transmission)

Last night i ran a 350 meg torrent and i had the wifi drop out so that problem persists even with 1.02. I was able to do a dmesg as Serge suggested and i see DMA transaction error with device 43 but i have no idea what device 43 is... anyone have an idea? I've attached my dmesg log in case anyone knows how to decipher.

At this low level i can only hope others can shed light. The wifi issue does seem system wide though since other apps like SSH can do the same.