Laptop trouble

[rwrw1]

I have an older IBM thinkpad 600e I use when I'm away from home. The computer has 128mb ram and 6gb HD. (I think) This is what I've noticed and was wondering what it is.
When I first start up the computer the normal black screen apprears. In the top left hand corner there is a number. This number is normally 136xxx, but sometimes it boots up and the number reads 006400. When it boots with the 64 number in the top corner the system is very slow to load so I just keep turning it off and on until it shows the 136 number. Anyway I figure this has something to do with my RAM but not sure. So just wondering if someone could tell me why this number changes and how I can fix it? Is one of my memory sticks not being booted?
Thanks

ps I run windows xp on this so it's overworked alot.

[EzyStvy]

Lappies run in a slower mode when on battery power. Maybe your power connector isn't connected well..

[thefultonhow]

That may in fact be the RAM -- try opening the door where the RAM is located and reseating both modules. If you're still getting the problem, run MemTest86+.

[rwrw1]

How do I run the mem test you suggest? I have already takin both my modules out and put them back in but I have the same trouble. Thanks for the help

[glc]

http://www.memtest.org/

Download - Pre-Compiled package for Floppy (DOS - Win)