K10D newbie question on storage cards.

I have a K10D with up to date firmware. I use it on a daily basis. I buy all my memory cards from Wilko. I am currently using a 16GB SDHC Class 10 ( up to 45MB/s ), Integral Ultima Pro. Very happy an no issues.
One other post here mentioned using micro sd cards in an adaptor, i tried this with two different sized cards and both failed. So switched back to SDHC.