I have exactly the same intermittent read problem with the Aspire 5100
in that the 1GB SD cards sometimes read first time but often not until
taken out and put back in again. Sony memory sticks cause a complete
system reboot.

However the card reader will not read any SDHC cards (which most of
the bigger cards are ie. 4 - 8GB ones). Is there any driver update for
this device? I cannot see one on the Acer site that will work with my
laptop.

Rgds., Roy