after playing around for about an hour ive managed to get it working. they key thing for me was uninstalling existing software/drivers.
so my quick rundown of what i did (Windows 7 SP1 x86/32bit):
1. deployed xap to phone
2. turn off mobile internet and wifi (leave 3g on)
3. open dfrouter and tap htc modem
4. uninstall htc modem that gets installed automatically, ticking the box to delete driver files.
5. scan for hardware changes in device manager
6. 2 unknown devices that need drivers:
M_00 needs htcVcomV32.inf
M_01 needs htcusbmdmv32.inf
both these files are in C:\Program Files\HTC\HTC BMP USB Driver then 1 folder for each inf file
now i have 2 devices:
HTC USB Modem under Modems
HTC Diagnostic Interface (COM4) under Ports (COm and LTP)
7. in advanced properties of htc modem, add +cgdcont=1,"IP" ,"general.t-mobile.uk" to extra settings (quotes needed)
8. in advanced port settings, change COM port number to 4
9. in network and sharing centre, click setup new connection
10. create dialup connection, dialing *99# (NO username, NO password)
11. wait for windows to create and connect to phone. get as far as authenticating computer on the network then appeared to hang but it did finish THIS TOOK 3 MINUTES!!
12. reset phone and pc
13. connect phone in usb modem mode using dfrouter
14 connect to dial up connection
to prove it is working, i am now connected only to the dial up connection (i called it t-mobile), wifi is off, hamachi vpn is off. it is pretty quick, certainly good enough for checking emails and facebook
my phone is a HTC HD2 running a WP7 7008 spoofed ROM
DISABLE VPN SOFTWARE!! this caused massive problems for me, i disabled it and all was well (disabled the virtual adapter in network and sharing centre, not just disable the software). i also found that skype and windows live messenger slowed the connection down a lot, so closed both of those.
so it does work, just requires a bit of know-how and common sense!!
to get back to zune mode, i just tap zune mode in dfrouter, the phone reeboots and it connects as normal (not sure if it matters, but i kept my usb cable connected)