K800i - computer won't recognise the device

Whilst shutting down my SE K800i a few days ago, I may have removed the
battery too quickly (ie. whilst it was still shutting down). Now it won't
switch on. When I try to power-up, an LED in the infrared port flashes about
6 times rapidly. Occasionally it comes one for about a second and doesn't
flash.

Reading about many similar problems, it sounds like the EPROM is likely to
be corrupted and the problem could be easily solved by reflashing...BUT here
lies the problem:

The phone is no longer recognised by my PC (running windows XP). There is
nothing wrong with the data cable as it works with a different SE phone on
the same PC. When I try to plug the phone into my PC, NOTHING happens. The
LED in the infrared port still comes on when I try...

Does anyone have any suggestions as to how I can solve this one as I don't
fancy sending it to SE and waiting weeks and all the problems that go along
with sending something in the post.

Any help would be greatly appreciated.

Many thanks....