Linksys 941 Dialplan Rules (Interdigit Timers not used)

I’ve been doing some testing with the SPA941 and although a great phone, I can’t get the dialplan string to work so that on a match it dials straight away without having to press “dial”.

the dialplan match i’m trying to use is simply 4 digits:

 (xxxx)

Interdigit short and long timers have been set from 0 through to 10 at different stages. The call NEVER gets initiated (at the phone level - as in it never hits asterisk). I’ve also tried

 (xxxxS0)

however to no avail.

The firmware I’m using is 4.1.5

Any help would be great.