It depends on the quality of the particular memory you're using. I have some PC100 that's stable up to 136MHz, so it's definitely possible. If your mobo has a 4:3 setting, "host clk -33" or similar setting, then it won't matter since the memory would only be at 100 when the cpu/fsb is at 133. If trying to run the memory at 133, use the slowest timings available as a start, and bump the mem voltage (vmem) from 3.3v to 3.5v if your mobo has such an option. Failing all that, then yes you're memory limited and will only be able to run at whatever speed the memory is capable of...but you've got to find out what the memory limit is!
my 1.8a will do 150 fsb on default voltage, even with the fan unplugged. these chips cost less than $140 now, but i paid $205 for this purticular chip, and if the price is right, it might go to the next person. and it is guaranteed to do 150 on below default voltage. gotta love sl68q.
Jdmcnudgent does you chip get any hotter? mine with air cooling was 36c idle 43c full load @1.8ghz and still has the same temp @2.2ghz default volts i guess if you dont up the volts it wont get hotter?