I also bricked my Neo2
512MB cart.

Neo Menu V2.95 just crashes right after starting if the bricked Neo2 512MB cart is plugged, V2.98 and 2.99 just give the "USB Device Error! Please replug USB device and try fresh again!"
I'm using Win XP 32bit SP3, tried it on three different XP PCs and also used different usb cables and different usb ports.
My Neo2
SD Cart formats just fine, but until the SD Menu is released it is kinda useless.
Does anyone that bricked his Neo2 512MB cart also uses Avira Antivir as Antivirus program?
Because normally I disable Antivir before I flash or format but this time I just forgot it, Antivir popped its stupid virus warning and my Neo2 was bricked since then.
About unbricking, are there any pins I can short on the Neo2 512MB cart to recover it or something like that?