The above line makes me think there was an error during the creation of the disk image on your new USB drive. Did you use a tool such has h2testw.exe (available in the "Tools" section of the downloads page) to verify the USB drive before installation?<3>VFS: Can't find ext3 filesystem on dev sda1.
If your new USB drive is okay and a dd copy of the v3.0 image reports success, but you are still having problems like the ones you mention above, then I'd suggest that you try installing the v2.6 disk image (which I can personally verify works) and then incrementally upgrade it to v3.0 after successful bootup.
(update):
I've looked at my own dmesg output and here are the only differences up until the point your bootup fails.
Yours says (about 12 lines from the bottom of your dmesg output)...
Whereas mine (which works) says...<7>sda: Mode Sense: 45 00 00 08
<3>sda: assuming drive cache: write through
<6> sda: sda1
After that mine goes on to start the EXT3 file system and does standard data checks and bootup, while yours starts outputting the error messages about not finding the proper file system and other problems.<7>sda: Mode Sense: 23 00 00 00
<3>sda: assuming drive cache: write through
<6> sda: sda1 sda2 sda3
I'm not a Linux expert so I don't know what "Mode Sense" means or if that's important (it could just be a difference having to do with different brands of USB stick), but clearly your disk is missing two partitions (sda2 and sda3) and that means the disk image did not install correctly.