You can always do the manual update if the OTA update wasn't successful.

Manual update instructions:
Since this is a patch file and not a full update, it will only work if you update from stock 2.1 (I am not 100% sure but I think it’s EA28).
Download the file from the mirror above and make sure it’s named update.zip. Make sure it’s not update.zip.zip (in case your Windows is set to hide file extensions).
Copy it to your Fascinate’s SD card using any method you fancy.
Reboot the phone and hold VolUp+VolDn+Power while booting it back up.
You should see the Samsung logo. You can now let go.
At this point, you should be in recovery. Use volume buttons to navigate and Home to select.
Scroll down to Apply sdcard:update.zip and select it.
Watch the magic happen.
Congratulations, you should now have Froyo on your Fascinate.
Here it is –
ED01 on our Crate mirror (97.95MB) – make sure it is named update.zip. Instructions coming up shortly.
Thanks for
androidpolice for these instructions.