Hello, folks.
I have an i5800L made for the Latin America region (Brazil, maybe - my locally-owned cellular provider buys phones wherever they can get them for a decent price) & I'm in the southern US, so no official froyo update through Kies for me. I bit the bullet and upgraded my phone manually with Odin. Samfirmware has a 2.2 file for what they list as USA (pretty sure it's for Canada), so I flashed my phone with that and turned my i5800L into an i5800D.
I started setting things up and noticed that the IMEI line was missing. It hadn't become zeroes, it was just gone from the phone status, and the network type had become GPRS rather than UMTS, which is what I had before. I had phone & data service, though.
I rooted my phone & started restoring my backups, then the whole thing froze up. I rebooted, and the phone would't get past the GT-i5800D screen. I tried re-flashing, and it got as far as "Deleting files please wait". I had a long moment of panic, thinking I had bricked my phone. Ultimately, I ended up downgrading back to 2.1 and trying the upgrade again with a different (European) 2.2 file (XXJPF), which also worked. Once again, my IMEI number didn't show up in the stats. I later discovered that by typing *#06# I was able to check it, and the IMEI was correct. I guess I should have known it was, since I had phone service. I'm a n00b atAndroid stuff.
At any rate, I now have an i5800 2.2 phone that feels brand new.
The Network Type is once again UMTS, although I lose service if I switch to the WCDMA Only option, which I could do with the original firmware. It works in Auto GSM/WCDMA mode, though. I have full 3G/HSDPA capabilities. It's rather annoying when it drops down to Edge, but I can live with it. The main reason I even upgraded was so I could use the wireless hotspot feature of the phone to connect my new unbranded Chinese tablet to the internet when I'm on the go (and it works fabulously, btw!)
Big thanks for the step-by-step instructions and all who replied with their results, both successes & not-so-successes. I really like my little phone, even though it's an "everywhere but the US" model. I think it's a shame, though, that Samsung hasn't released the upgrade worldwide. I'm sure there are a few Brazilians who would like an official upgrade.
Have a great day!