Audio Recording Working Sporadically Since 4.5 Upgrade

Question

The audio recording feature we've built into one of the activities on our educational website has been faultering since our recent upgrade to FMS4.5 .
We're using the "publish" feature of NetStream.
It seems to work fine for a while, then it stops working.
Has there been a change in the 4.5 update that may be the cause?
Is anyone else having this problem?
Thanks,
Mike

Answer 1

Thanks for your response, SE_0208. 
We're simply attaching audio that's incoming via the user's microphone to an instance of the NetStream class, which show up as .flv files in the application's "recordings" directory.  Code snippet as follows:
     var nsRecord:NetStream = new NetStream(ncRecord);
     nsRecord.setBufferTime(2);
     var mic:Microphone = Microphone.get();
     mic.setRate(11);
     mic.setSilenceLevel(1);
     mic.setUseEchoSuppression(true);
     nsRecord.attachAudio(mic);
     function playRecordedAudio():Void {
            nsRecord.play(fileName);
It's worked without a hitch for three years, (and we get 10,000 visitors a day), but ever since we updated to FMS 4.5, it'll work fine for a day or two, then it suddenly stops recording the files.  (No new files show up in the recordings directory). 
One clue, in case it helps, is that when the problem arises and it quits working, the Flash Media Administration Console shows a huge number of Active Clients, (1000+).  When it's working fine, that number is significantly smaller, (around 20).   I'm wondering if it's failing to recognize when users have disconnected, thus accumulating and maxing out on Active Clients and crashing the application.  
Your thoughts?
Thanks,
Mike