I'm gonna have to agree with crackman, I suggest going to the doc, you might be experiencing arthritis or something along those lines. My hubby suffers from pain in his joints, he has some kind of immunodeficiency disorder (IGA or something like that, don't really remember). Anyway, point he is generally in a lot of pain, although he's never really cracked a joint in his body but the main areas of pain for him are his fingers, wrists and ankles.
Get yourself checked, rather be safe than sorry.