@ponce; I installed your kernel 21 May image with 20 May kernel yesterday and had an error message when installing the raspi-extra kernel
Executing install script for kernel raspi-3.6.11_20130520-arm-1ponce.tgz
sed: couldn't flush boot sed yamYEL*: no space left on device
I wasn't sure if the install would be any good so I dropped into a terminal and checked /mnt/boot. Everything seemed to be in order but I deleted all the READMEs and installed the kernel again just in case. I didn't have any errors that time and could boot slackware arm current but I decided to reinstall again with a larger boot partition. so I dd'd that card again and then used gparted to enlarge the boot partition. Gparted gave me 88mb for the partion size and said 87.34mb were used. I enlarged it to 100mb and then added an ext4 and swap partiton. Install was fine and the pi is now blue tacked to a wall out in my shop and talking to me via wireless as I write.
Should I have had 87.34mb used up in that boot partition after transfering your image to a card and installing as per your packages. If so an 88mb partition seems a bit small in case the kernel is replaced with another one a bit larger.