Hi, only just noticed the reply. Cheers.

I've left training completely since and taken complete rest since i first sent the post. I've been under the weather as well. I took voltaren for a couple of days, and it did me no good. It caused nausea, drowsiness, depression, and may have even increased the pain. I went back to ibruprofen (400mg) 4 times a day, taking doses of paracetamol in between (2 500mg tabs). I feel much better now. The pains almost gone now, and hopefully I'll be going back to the gym on Saturday!
The pain occurs during military press, shoulder press, or lateral raise, when my upper arm is just less then perpendicular to the torso until a little more.
What I need to determine is what caused it, (i didn't feel it suddenly during a workout - just woke up one morning with it), and what precautions I can take to prevent it happening again.

Any thoughts?