Error message when upgrading Galaxy S to Froyo So I finaly got a copy of Windows and installed VMWare on OS X
After fidling with driver issues etc. etc. I got the Kies software to recognize the Gallaxy S

After Kies had downloaded the upgrade files and started (an image of the Android raking leaves on the phone screen) this message pops up

"failed to convert to upgrade mode"

Does anyone know what the problem is? and how to get around this?
The picture you got on your phone was upgrade mode (also called download mode).  The phone disconnects and then tries to reconnect when it goes into this mode.  My guess is that the reconnect failed; it happened to me when I tried upgrading through a virtual machine.  I suggest borrowing a friend's computer running Windows natively to do the upgrade.