OK, let me see if I can remember everything that I have done. (Bear with with my please)

1) Soft-Reset my i760
2) Installed the ICSInstall.zip from this thread: Internet Sharing over WiFi - WMWifiRouter v0.89 (Jan 7, 200 - xda-developers
and did the following (note, not all of the steps!)

Download the attached ZIP file
- Extract it somewhere on your computer
- Copy the CAB, EXE and BIN file to your mobile device
- Install the CAB (just run it)
- Run ICSInstall.exe
- Click "Patch"
- Wait 'til it says "Done"
- Close the program
- Soft-reset

3)Installed WMWifiRouter from here:WMWifiRouter v0.89 (Jan 7, 200
I used the CAB version with the network settings, and downloaded it straight to my device. Before installing I soft-reset after the ICS install, and then turned Wifi ON. I then proceded with the install, and then Soft-Reset again.