Just like to say thanks to those in the forum keeping this information flowing.
My son wanted 2.1 on his UK t-mobile galaxy portal.
A quick re-cap of my steps for those that are nervous. (i'd never done this for the galaxy portal/spica before). Based on reading the threads so far.
1.Removed all previous samsung apps & samsung named drivers via uninstall programs - on 32 bit win7 home premium with all latest updates.
2.Installed latest Kies (was v1.4) from samsung to get latest usb drivers, closed Kies after it started up automatically.
3.Run odin 4.03 with spica.ops that came with 4.03 and all firmware files from I570EXXJE4, setup odin , then connected phone in download mode (vol down + camera + power off)
4.failed - hung after flash with phone exclamation mark
6.run odin again with spica-jc3.ops and all firmware files again just in case, then connected phone in download mode (vol down + camera + power off)
Could probably have skipped 3 and gone straight to 6 to avoid hung phone problem.
All together took about 10 minutes.