I've got a HP 2510, which I've been happily using for faxes running of the properties residential line. Since then I've had a couple of business lines installed, one for calls and one for faxes, but the 2510 seems to be having problems with it.

The lines are of the type where you have to dial '9' before it opens a line to the outside, and the fax machine seems unable to deal with the concept, even if I type nine before every fax number I enter.

When the machine is running off the residential line, as soon as I hit dial I get a dial tone, followed by the number's tone, but on the business line I don't get the dial tone, just the number's tone, followed by a ringing tone that doesn't actually ring through...

Anybody got any ideas how to get around this? I checked the manual and it doesn't seem to have a dial prefix option, and unless there's fix I'm going to have wasted a bit of cash for a line I can't use.