Connection Trouble

Anyone help with a modem/connection problem ?
I have a USR V90 modem ( ext ), XP1800 system, Win Me, IE5.5
The modem dials out and connects to ISP ( Onetel ) It exchanges a few bytes and then does nothing. It shows a connection speed of 45-50 kb but will not access anything via IE. I have re installed the modem, drivers, IE and looked at all the settings. Everything seems ok. I have tried another ISP with the same result. I can connect via another PC in the house- phone is ok. Anyone have a suggestion what the prob could be ?
Thanks .

u havent got a firewall running do u? also what connection does ur ext use usb? printer? comm? what are u port connection settings?

Norton Firewall but disabled, serial port connection, com1, settings seem ok