I *hate* compaq. Ive never worked in a Compaq machine without some kind of trouble somewhere. Inclduing a nasty gash off of cheaply machined steel. Did I mention I *hateHateHATE* compaq?
Right, lets think about this. Any time you have the new chip in, the machine wont boot. First thing we think about is a defective chip. Do you have access to another machine that you can get into? Preferably one thats owned by someone who knows this sort of stuff. If so use that to check it out. Its rare but sometimes the chip just wont work.
I dont think Vaskez' theory of not being able to run PC-133 applies, since the memory site I showed you did recommend a PC-133 chip. Also as I said, specs say PC133 should always work in a PC100 machine.
http://www.wimsbios.com/ has a facility for IDing a mobo from a BIOS number. Once you have the specs on the mobo itself we should be able to see if there are any good reasons for it not working.