Acer aspire 5100 model- BL51 aka. Aspire 5100-4720

Just talked to Crucial Tech for half an hour or more.

They Said that the Bios version I had, (1.9 I think)
needed to be updated. She said it was a well known
problem for this laptop.

The latest version is 3 point something to be found on
acer's site. She advised me to put the old memory
in and get the system stable, and then follow the instructions
to flash the bios.

I'm working on one right now for a customer and threw in two spare 2GB SODIMMS from a Mac PowerBook PPC circa 2004. It booted up great and is faster than ever.

The mem I used was 2GB 2Rx8 PC2-5300-555-12