Call Forward number is invalid

[terrys]

We have a NBX V3000 Analog.  I'm trying to setup a call forward to a cell phone for a user.  At the Personal Settings, User Information, Call Forward Default screen I select Forward to phone number and enter the cell phone number.  When I try to apply this a warning comes up that says "Call Forward number is invalid".  I can click yes to ignore the warning, but calls are not forwarded to the cell phone.

I've tried entering both a 7 digit number and a 10 digit number.  We do not have to dial a number to get an outside line.  Call Forwading to an internal extension works.  What do I have to change to use an external number?

[merlin215]

Should be a 91xxxxxxxxxx number .... ( 11 digits plus 9 =12 ) 

I cannot see the system saying it is an invalid number unless the number is an internal number or something else in the numbering plan . 

it could be something like trunk to trunk forwarding enabling , COS info correct etc . 

[bosoxfan]

I know this seems strange, but we have seen "number invalid" if using the wrong browser.. what browser are you using? IE 7  or below is supported...

If using IE 8, try compatability mode.....