IE7 Downloads much slower under Vista

[Hula Baloo]

I'm getting 40% of the download speeds using IE7 vs Firefox under
Vista. E.g. one test I benchmarked gets 1200 KBps downloads with
Firefox but 500KBps with IE7 under Vista. If I boot XP (I have dual
boot on this machine), I get the same good speed with IE7 and Firefox.
My configuration is:
3.2 GHz P4 with HT
1GB dual-channel non-shared DDR3200 RAM
10,000 RPM SATA HD
7 Mbps cable connection to Internet
Suggestions, comments welcome. TIA

 

[Hula Baloo]

Anybody know why IE downloads are so much slower under Vista? I
don't understand it. If anyone knows, I'd sure love to hear about it.