Ongoing RAM problem ibook G4

Hi all. An ongoing RAM problem I seem to continually experience. I have checked that the RAM specifications in the ibook G4 manual corresponds to the RAM I have purchased (512mb ddr sodimm pc2100 266mhz 200 pin). I have grounded myself when fitting it. It is brand new from the ebuyer website and wont register in my system profiler. Tried doing this before with some ram i bought which also didnt work. If anybody can shed some light on the situation I would be most grateful as I desperately need to be able to utilise this new RAM for my video editing and web design needs.
Thanking you all in advance. tom.

Maybe this should help, usually, when installing ram, seating is the problem.

http://www.mac-forums.com/forums/showthread.php?p=141113#post141113