When I was trying some new forehand and serving techniques I got some pain on the ulnar side (pinkie). See the USTA wrist injury discussion in a link in the second TW thread.
Thread on serve. See reply #167.
Can you get a high speed video of your serve? A 60p DSLR with a fast shutter, 1/2000 sec, etc might do also but you might have to video several serves to see wrist angles.
For the forehand see especially the Charliefedererer replies and links.