My friend has a Samsung i9000 (Captivate) Model SGH-i879
The firmware version before they rooted and modded it was 2.2 Froyo. I'm not going to edit what they're saying because I don't know anything about flashing roms for androids.

Currently all it does is boot loop to ROM mosiac v2.0 and its able to two button (down and power button) go download mode.

When they turn the phone on it goes to the Mosiac boot screen and it just stays there.
If they try to boot to download mode all it does is go to the battery charge screen. In order to get to download mode, they have to volume down and power button, which is the two button download mode.
And they can't even get into recovery mode, it just turns the phone on, which goes back to what I stated previously about it staying on the mosiac boot screen.

I have some pictures I can post if need be.