Hello, I am completely new to photography, and this question probably has a very obvious answer. Anyway, I have an Olympus E-520 with a 4 gb SanDisk Ultra II Compact Flash. When i first got it all, i was able to take 300 pictures or something like that, and now i am at 29 pictures left. I wanted to free up some space on the card, so i deleted a bunch of photos, but the number stays at 29. Any suggestions?