Unless I am reading this wrong the only way you will be able to have x 2 press a button and get into x 1's vm ( checking messages that is ) is by using a system speed dial list because both ext's will send there calling party ID to the VM hunt group. You will need to trick the system with a seed dial something like this-

1.- speed dial acces code plus bin *9+ 100

2.- *9100 = (vm HG)*9=(pause) *** ( i believe this = a *) *9=(pause) (insert x 1 here ) *9=(pause).
Exapmle=*9100 5500*9****91*9

3. this should get x2 to hear " please enter your MB # then PW

Of course set you cos option 245 and system option 21

then you should have to program the speed call under a button.

I hope this helps,It will of course need some testing and tweeking within the speed dial bin. Refer to your docs on the different strings for form 31

Alex Kroger
Pinnacle Communications Corp
Mitel/Hitachi
Nationwide Hospitality Provider