What camera do you have? That will tell us a lot. If it is say a Canon XSi then it should be no issues, if it is something a little bit older it is hit & miss where the higher end devices might be hits and the lower end models misses, if it is a few years old and pre SDHC then pretty much miss all the way through.
Then of course there is the file system, my old Fuji camera only supports Fat16 & 2GB cards and I had to email them to confirm this as back in 2003 when I got it large cards werent all the rage