can't ping HiPort adapter, but can login to it. Blue light on.

Just tried setting up my new HiPort adapter for the @home service. I have an existing Linksys wireless router that I wanted to keep in place.
After many iterations I finally have it close to working, but not quite. I have it setup as :
cable modem (comcast) -  existing router  - new HiPort adapter.
The existing router is my DHCP server and gateway - the HiPort is setup as a bridge (in advanced routing config page) since I really only need to use it to hang my phone off of. I can connect all my computers to the existing router, both through wired and Wifi, and can connect to the configuration pages for both my existing router and the HiPort. The Hiport has it's blue light on, but if I plug my phone in I don't get a dial tone. I also can't ping out to my existing router or any computers on my LAN from the HiPort Administration:Diagnostics page.  But it is getting a IP addresses dynamically from my existing router and I can ping it.
SO it seems I have a halfway connected HiPort.

My existing router is a WRT54G (linksys) and is setup as a Gateway.

I do have a good SIM card in the HiPort - the Voice page in the HiPort configuration says the sim is registered.

HiPort is configured via DHCP with
IP Address  :    192.168.29.102       
Subnet Mask  :    255.255.255.0       
Default Gateway  :    192.168.29.2

The WRT45G is setup to have local IP 192.168.29.2.

Any ideas ?

Instead of pinging from the router, try run a ping and tracert from command prompt.  If anything, TMo Tech Support should have a good idea of what's wrong and how to fix it.

I have a nearly identical setup as you do, and my Hi-port has worked flawlessly since day one. My setup is Comcast cable modem(Linksys CM100)->WiFi router(Linksys 610N)->Hi-port. I used all the defaults on the setup disk that came with the Hi-port. My Hi-port is set to Router on the advanced routing config page, not Bridge, so you may want to try changing that.

You may also want to double check your connections. If the blue light is on and you don't get a dial tone, you may be connected to the wrong phone jack. You may have accidentally put your sim card into the second sim card slot, so your dial tone would be on Phone line jack #2. Good luck.