said by fozngoof :

Might double check the user name again, on both ends.

Make sure it is "UserNameHere" and not "UserNameHere@IspNameHere"

Sometimes you might need the whole thing.

Also double check for differences in lower-case and upper-case spellings in the user name and password.

Just throwing ideas out there.

said by Squidii :

In my experience the ISP probably isn't running to separate authentication systems for ISDN and it's dial up business, so in order to test my username and passwords without the complications of ISDN I would use a modem and phone line to call in and test.

But like fozngoof, I'm just throwing ideas out

said by IanelarAzure :

[The ISP, IgLoo, does offer dial-up and ISDN services. Ill check with them to be sure we are not confused on what service she has here.