FMIS 4.5 bandwidth detection problems

My problem is that FMIS 4.5's bandwidth detection is incorrectly reporting the quality of the client's available bandwidth over RTMP dynamic streaming. I have an F4M manifest file with three media entries, one at 1300Kbps, one at 700Kbps, and one at 300Kbps. I'm using the demo player built into the FMIS webroot so I can see the graph of bandwidth as it changes. The player starts playing the 300Kbps version, then ratchets all the way up to 1300Kbps after about 13 seconds, and then goes all the way back down to the 300Kbps version five seconds later and stays on that version. I've duplicated this problem on four servers, one a physical server in our datacenter, another a virtual machine in our VM farm, and two servers that are VMs on my local computer. Every time, the same problem occurs, at the same time in the video. I've tried changing all the settings I can find relating to bandwidth, buffer, and whatnot, to no effect. The problem persists no matter what I do. You'd think that an FMIS server as a VM on my local machine would have more than enough bandwidth to play a 1300Kbps video. The server never has CPU, memory, or disk IO spikes during playback.

Any ideas? I would rather not have to write my own bandwidth detection scripts, I'd like to think that the ones built into FMIS and Adobe's own FLVPlayback could handle this.

Thanks for any help.