Stuck in Bootloader... but did no upgrade!

[urinsane]

About half way through the day today, my phone reset all by itself. It is now stuck in the bootloader screen with "serial" at the bottom.

I had not tried out any custom ROMs, and was using the newest official Sprint Mogul ROM from HTC's site. This phone is fairly new; I did an insurance swap on it last month. (Not a refurb strangely enough) It had been running the new ROM since.

When I plug it into USB, "serial" changes to "USB", and my PC identifies it as an unknown device. Activesync does not seem to see it at all.

So first I tried downloading the official Sprint ROM again. Surprisingly it ran the ROM update and seemed to install just fine... progress bar and everything. When I disconnected and reset though, it was back to bootloader.

I have played around with custom ROMs before (on my old phone; the newest Sprint ROM had everything I needed with less hassle though so I hadn't installed any on this new phone) so I downloaded the Titan Bootloader Exit app from here. I disabled Activesync USB, ran the exe, but get the error message "Cannot Open USB port".

I'm running out of ideas and have tried just about everything recommended in other threads. Hoping someone can help!

Thanks!