I now get pretty slow write speeds (around 200 to 300 KB/s) with several (micro) SD cards connected to a USB card reader ("Super Top" - Vid/Pid: 14cd:125c) in Ubuntu 12.04.

The performance was never great with this card reader, but recently it has really gotten worse. I don't see any error/warning messages in dmesg, and I'm not sure how to debug, or better solve, this issue. Any ideas?