Brush problem in PS7

Quick question, I scanned the memories and didn't see anything: I use PS7, and sometimes when I go to use a brush, it only shows me a pinpoint and not what the actual brush will look like. Usually it'll give you that "preview" before you actually put the brush on a pic, but every once in a while it'll just go to the pinpoint (but the brush will still work) and I can't figure out how to change it back to the "preview" setting. I'll shut down and open the program a few times and finally sometimes it'll work, but never if I just shut it down once. Is there something I'm doing wrong and I don't realize it? Any help is appreciated, thanks.