CompuServe Messages

My Amiga 3000 is giving me problems. Sometimes it just freezes up. Other times I get a nice orange box on a black screen with the message error 8000 0004, task 0748 2f40. Of course, this message is nowhere to be found in any of my AmigaDOS manuals. Does anyone know what this message means? I have the 2.0 ROMS installed, Kickstart V 37.175, WB V38.35, 2 MB Chip ram 12 MB fast ram. I added memory a while back and it seems that these occasional problems started happening then – but it is hard to be sure. I'd like to test the memory to be sure that it is OK. I downloaded the latest version of the MEMTEST program from the database here but it freezes up too. This is an older program, does anyone know if this program will work properly on a 3000 or with WB V2.x? There are at least a couple of commercial programs that claim to diagnose problems with your Amiga, does anyone here have any of these programs? Are they worthwhile or not? How does the Amiga operating system allocate FAST memory (i.e. does it start allocating memory from top down, botton up, etc., if I knew this I might be able to try loading various in various orders and try to track down the problem if it is indeed memory related)? Thanks for any insight you can provide, -J