mp3s are streamed from disk, not loaded to RAM, so problem with lag may be slow hard drive.
Can you send me crash dump? There should be folder in game folder named date and time of crash.
Sadly, I've deleted the crash dumps. But I'll report in when it crashes again. Also, I've been wrong on the part when I said that the cassetes don't fall through the floor. They do, but it's more rare now than ever, so it still is awesome!