Bug Fixes & Upgrades to YouTube-Like Video System

We have a Flowplayer/FFMPEG based video upload and playback system, and it's quite buggy, laggy, and needs some refinement. Users have trouble with uploading videos, playback can be choppy, and it doesn't support HD very well. We aren't looking for a complete overhaul, but some bug fixes and possible upgrades. The video system is currently live, and we would like to minimize downtime as much as possible. MUST have experience working on similar type of video systems, and experience with Flowplayer and FFMPEG is a huge PLUS! Send me links of other video systems you have worked on so we can evaluate. You can view the current video system here: [login to view URL]