OE connection breaks

[idr]

I am working at home on a ~2GHz computer, win98 se, IE6 and 0E6, with a dial-up connection to the internet. As my onboard modem didn’t work I installed lately a PCI modem. Now, when online and try to open the Outlook Express the OE window opens, but the program doesn’t respond.
When I click the „send/receive” button the connection breaks up and a new dial-up window appears.
In order to avoid this I checked the „ask before switching” box at „options-connection”, but then, every time when opening the OE a window appears asking if it should switch the connections.
When I uncheck again the box, the connection breaks again, and I must reconnect before receiving the messages.
It is not a serious problem, simply annoying, but there is certainly a way to avoid both the pop-up window and the connection break, however I still cannot find it.
Can anybody advise??
Thanks