Phones at remote site not functioning

[strai]

Hi everyone,
I have got an Avaya IP office 500v2 setup here at my central office and am having some trouble getting the phones to work properly from my satellite office. we have been functionally abandoned by the vendor who sold us the system, their only trained tech quit and they dont take my phone calls anymore, so i have been figuring out how to do this myself.

Here is my scenario:

i have an IP Office 500 v2 system at my main office and i have it working almost perfectly. All of our phones are 9608 models. I have a satellite office with a different subnet that is connected to the main office by a persistent point to point vpn. i have put in the appropriate options in the dhcp config and i have added an ip route out my internal interface to the subnet of my satellite office. when i plug in a phone at my satellite office it finds my system and downloads firmware. it even allows me to login to the phone with an extension designated for the satellite office.

Here is my problem:
once I've logged into the phone i get nothing, none of my configured buttons, i cannot call any of my other extensions, i cannot call out. if i lof out of the phone and try to log in with a bogus extension i get a login failed message, so it seems to be communicating with the system on some level. when these phones are logged in the extensions dont show as registered in the system status utility and i dont see any traffic from the satellite office subnet in the monitor program.
my firewalls are logging traffic to the system and there is nothing impeding the traffic flow.

My question is:
where do i start looking to troubleshoot the problem? what am i missing?
thanks in advance for any guidance.

[peloq]

Your phones dowloaded the files from the Voicemail Pro PC or the IPO SD card?

[strai]

yes it downloaded the files just fine. brand new phones out of the box find the system with the IP "helpers" download the appropriate files, saves them to flash, reboots, requires you to login, then nothing.