maybe there is a timeout problem in your environment. When you browse your library, could you please check if your FireFly Server is scanning the MP3 folder at the same time? Maybe the NSLU2 can not handle it all at the same time. I figured out that the whole NSLU2 become slow when the FireFly Server is performing a scan. I also discovered that setting the debuglevel to 9 increases the time to scan my MP3 folder. Actually it took longer than 10min and I configured the scan interval to be 10min so it scanned all the time.
It’s just to give you some ideas where the problem can come from.