wal-mart and CF

so far i've bought three compact flash cards from wal-mart.

mostly because i'm lazy.

they're all SanDisk, and some of them are labeled.

for my d200 i got a ultra II 15mb/s.

for the 40d i got one that says 30mb/s but there's no indication whether it's a CFII or CFIII... i have no idea what the hell it even is.

for cameras that aren't that fast to begin with, does it even matter?

Your fine with what you bought as they are Type CF Type I. Microdrives are a Type II form factor.

You're fine. The regular Sandisks will perform well for either.

Well, they're all CF Type 1 (which is a thickness, not a performance measure). If you got an Ultra that's rated at 30 MB/s it's an "Ultra". Ultra is a product name, not a performance measure, and it's replaced their "Ultra II" cards. And it should be good for the 40D.