This is exactly what has happened with mine, luckily I've got the ZXi so I use the remote thingy, but eventually I reckon I'll have to pull it all apart to clear out the crap inside it.
I hope that with the opening "open" not to much rubbish will get in to it, but in the long term, who knows? This has been the case since March.........
It is possible to take it apart, but be careful of flying springs...
Another thread on this forum might help:
[url]http://www.maz323f.co.uk/forum/viewtopic.php4?t=307[/url]