The other idea I have looking at the changes between build 1488 and 1489 is issue
http://www.ventismedia.com/mantis/view.php?id=9326
Do you have x64 platform?
Could you try the following test?
Patch the MediaMonkey.exe from the last working build (1488) by using these steps: http://www.ntcore.com/4gb_patch.php and let me know whether it fails to rip after applying the patch? It would confirm that it is caused by the issue #9326

