I forgot to mention, beware of counterfeit CFs. There is quite a lot of them out there, including SanDisk.

Things to look for - Blurry labels, colors a but off, Look-a-like lables (missing the brand name or logo), missing serial numbers (on one of the end of the CF there is a serial number put there by the company, counterfeit CFs usually do not have this number), when you format them they are a bit smaller in size than the name brand, they are slower than advertised speeds and a "too good to be true price."

Because of Counterfeit CFs, SanDisk and other CF Media Makers change their label designs few couple years. Counterfeit CF tend to have the older labels for the a longer amount of time.