FSB causing USB problems?

Hi forum

I recently started overlocking my pc and have had little success in raising the FSB, i can get it up to 137/37 but any further than that and my Alcatel ADSL Speedtouch USB Modem fails to initialize at startup.

I thought it may have been as far as my system will go, but with the modem unplugged i can set it to 145/45 and its perfectly stable(temp is 52 C under load). Any ideas what i can do to resolve this?
Im thinking it might be a power issue as i only have a 300w PSU.

my specs are :

Athlon t-bird 1.4 @ 11.5 x 137 = 1575mhz (tried lower multipliers but modem problem remains)
Asus A7v266 mobo
PNY GF4 Ti4600
512MB Crucial Ram
Onboard sound
Win XP Pro
Speedtouch USB Modem

the USB on my board act's funny after 140Mhz, so i try not to use anything USB. suprisingly my Nostromo N50 works at 154Mhz fsb.

anyway, my advice would be to use a standard RJ-45 modem. then all you have to worry about is the network card crapping out at high FSB settings. (most network cards i seen can do atleast 142Mhz fsb before they stop working)

also, USB modems don't perform as well as a RJ45 modem imo. i was using the USB off my SB4100 and when i switched to RJ45 my ping was cut in half

EDIT: oh yeah, WELCOME TO THE FORUM!!!