ninjabear: It's a hardware issue not a software issue so firmware upgrading will not help
I'm not certain about microSD, but it is possible to upgrade from SD to SDHC via firmware. I have an HP laptop that was only SD compatible when I bought it. HP subsequently issued a firmware patch to upgrade to SDHC, which I have done. I have seen similar patches for some cameras.
Another point - everyone seems to recommend Sandisk, but I have used mostly Adata and one Toshiba card so far without a single problem (other than forgetting where I stored a card!). That is just my experience. Its a very small sample so needs to be taken in that light.