If you can get to Settings/System Settings/USB try both MSC and MTP connections. One might work–the one you were using may have gotten switched during the update.
Otherwise, nuke it.
Try formatting the unit from its own Format command, under Settings/System settings. It looks like you’ve already tried that, though.
In Settings/System Settings go to USB Mode and make it MSC. Then connect to Windows and format the unit to FAT32 if that’s not what comes up automatically.
1.02.18 should be the right firmware.
http://forums.sandisk.com/t5/Sansa-Clip-Sansa-Clip/Sansa-Clip-Firmware-Update-01-02-18/td-p/280756
Unzip it and send clppa.bin over (MSC Mode) to whatever driveletter the Clip comes up as. Make sure the whole thing gets transferred.
When you disconnect it should show that it’s updating. I use MSC mode, but if you’re using Overdrive it may work better in MTP.
