Help Storage Capacity full & SD Card issue


Help. Every month or so I get a round disc icon in my notification bar that tells me I'm running out of disc space. Problem is I have only ONE app on my phone, Solitaire. I do not keep tons of text messages on my phone either. I do have a lot of photos (I probably have less than 150 photos) that I have set the phone to save to an external SD card, but when I pull the card out and insert into my computer, it says there are no photos. So actually, I have TWO issues: the disc space problem, and although I have the phone set to save photos to my SD card, it's not saving them to the SD card. However, after a week or so of this disc space notification, it goes away and I've not deleted any photos.

Also, the lag time on the phone is horrible. Anybody else have this problem?