That's not the actual entry you used, is it? You forgot to post the actual changes you made which you will need to do to get help. The entry you posted for Ubuntu in your initial post will not work when you are booting with Grub Legacy. Either of the options I showed you in my last post should work for a system with Grub2. I have used both on numerous occasions successfully.
Do you still have Tiny Core installed with its Grub Legacy bootloader in the master boot record?
Are you still able to successfully boot it?
Yes, Grub2 uses 'linux' in place of 'kernel' for the its entries.
Also, it would be helpful if you posted the output of the fdisk -l command run as root with an indication of which partition has TinyCore and which has Ubuntu.