Someone please help me before I throw the my N900/myself out the window!

I've been having issues recently with my N900 occasionally showing the SIM card symbol with a red line through it and also showing 3G signal but not actually able to make/recieve calls etc, so I decided a reflash would be in order.

I installed the flasher, flashed the firmware fine (without the -R option) but now when I come to flash the eMMC it shows the flashing dots for a few seconds, then freezes with the second dot white, whilst the flasher cmd window says "Suitable USB device not found, waiting". At the same time the hardware system tray icon reports there is a problem with hardware - but this message has always come up and hasn't been an issue.

I've tried rebooting the machine, disconnecting the phone, etc etc - all to no avail.

I'm running Windows XP (I think SP2) - does anyone have any advice for me before I go insane? It's so frustrating!