I've tried using your instructions for sfdisk formating as well. It leads to the same problem (booting from mmc will not work anymore). It just stays stuck on the Nokia screen with the blue bar loaded. After a while it reboots and I'm back at the boot menu.

Is there any alternative to low level formating? (don't have access to an SDHC reader).

Edit: I'm going try the directions in your blog Schmot's.
Edit: Same exact problem (I reflashed my tablet and redid everything following your blog post)

I'm beginning to think it's my SDHC card. -_- *sighs* (It's an A-Data 4 GB class 6 SDHC card).

Reading around it seems that it does require a low level format (possibly why it only worked the first time so it needs another one?). So maybe I need to go find an SDHC card reader..

Edit: (this is probably getting annoying now huh..? I apologize if so). Apparantly you can format your SDHC cards with the Panasonic formatter if you just leave them in the tablet and connect the tablet to PC. Off to try again now.

Edit: And it still doesn't work (even gave me the memory is corrupted error like it did the first time I was doing it like the guide stated when it worked.). *sighs*

I could try using my 16 GB card.. but I had originally intended on using my 4 GB for the OS and my 16 GB for external so I could always be loading data into it without much trouble.