WinPwn 126.96.36.199 worked fine on my previously pwned 2G iPhone. I also got both installer and cydia in my custom firmware. Here's what I did:
1. Choose Browse.ipsw and pick the official 2.0.1 firmware from Apple
2. Click on IPSW Builder
3. Select the options you want (in my case, I selected youtube fix, installer, cydia, and also the options to unlock my baseband since I'm not on an official carrier.
4. **I changed the partition size from 500MB to 1000MB**
5. Then i built my IPSW
6. Click on iPwner and select your newly built custom 2.0.1 firmware to pwn iTunes.
7. Open iTunes and put your phone in DFU mode
8. When iTunes detects your phone in recovery mode, click Shift-Restore then select your new custom firmware.
That's it. Restoring took a while, but I just left it, and then I had both Cydia and Installer on my phone. I'm restoring from backup as I speak.
NOTE: Building my custom IPSW with BOTH Cydia and Installer did not work until I tried changing the partition size from 500 MB to 1000 MB,!
do not forget this
before you install new winpwn version
uninstall previous version of winpwn
delete "cmw" folder in c: Documents and settings/USER/applications data/ and delete cmw