I've recently bought a DX True 100mW greenie. A strange circle-like thing appears randomly when using the laser, especially when I use it after a while. The guys over at DX forums told me that it may be dust. But I don't think that's the case because it appears sometimes, not all the times, but in the same place. I've already blown some air into the lens from the front and it didn't go away. I know it's hard to disassemble those lasers and I don't want to damage the shell. What should I do? I'm attaching a photo.
