dialup modem not being released when I disconnect

Hey.

I have a presario f572us with vista home premium.

I noticed that whenever i connect with via dialup and disconnect, I cannot reconnect unless I restart the pc. its very frustrating especially if I am doing a lot of work.

I think once it said that the modem is in use.

I reinstalled the drivers and still the same problem. Someone suggested installing and re-installing the DUN (dialup networking ) option, but I can't find it on vista. I don't think these newer OS allow such, since its a windows component.

How can I remedy this problem? Should I completely uninstall the driver and install the original driver that came with the system or roll back?

Thanks for any suggestions.

By the way, device manager says that the device is working fine.