Straight out of the IBM Engineers Manual...
Standard: 256MB
Max: 4GB
Type: 133Mhz, ECC, SDRAM, Registered DIMMs
Slots: 4 Dual Inline
Is the memory IBM memory or Generic. Have you updated the Bios to the latest level. Do you have a raid card or additional SCSI card installed. Once you get to 4gb of memory you get all sorts of memory issues as most drivers and card BIOS's error. There are changes that need to be made to the Adaptec Bios for instance before it will work with 4gb.
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