(I posted this a few days ago, but it disappeared -- this time I'll just synopsize)
Recently I installed the Quick Install utility but had difficulty running it. Novacom didn't want to run -- my Pre was seen as a USB device and assigned a drive letter (that I couldn't access) when I set it to "charge only".
While looking for the solution, I discovered that WebOSDoctor resets the phone and turns development mode off.
Even with it on, I still couldn't get Quick Install to see the device until I cleaned out the USB devices for the Pre and re-installed them. To do this, I used USBDeviceView from nirsoft.net.
It's FREE, and after using "File - Uninstall selected devices", I was able to get Novacom re-installed and working, where trying the re-install before didn't solve the problem.
Hopefully this helps others avoid the hours of frustration I experienced.