I've got a C1000 with Cacko ROM 1.23b and [...]
A-Data 2Gb - 29
The A-Data Turbo SD 150X 2G card also fails on SL-C3100 (standard ROM). Only thing I noticed is it caused the keyboard to behave erratically (e.g. backgrounding programs like Qkonsole); removing the card didn't fix the problem, required a reboot. I don't have any other cards to see if it fried the controller as other posters have suggested, though I don't think it should have.
--
Live well,
~wren
Elsamelys : SL-C3100 + standard ROM