I dunno, knees can be a real b*st*rd. Strange this thread was top of the current list on the RW homepage, hence my reply. I will be more observant in the future, promise.
Start cycling to build up muscles around your knee. I used to have intermittent pain from a torn ligament or meniscus, it was never accurately diagnosed. I started mountain biking more last year, done the odd Duathlon, and my knee is great.