I can't help with testing the kernel, but I had the problem in this bug report when I upgraded from a daily alternate image a few days after Beta 1.
I fixed my system by booting the recovery mode with "nomodeset" appended to the grub boot command, and then ran the manual nvidia install shown in the known issues for http://www.ubuntu.com/testing/lucid/alpha2 - the bit about Jockey not supporting the Nvidia alternates system. I then rebooted and the nvidia kernel module failed to load, but the vesa fallback worked. I then reinstalled nvidia-common and it worked, fixing the nvidia driver.
Hope that helps as a workaround, I don't know if it will still work at this point.
I can't help with testing the kernel, but I had the problem in this bug report when I upgraded from a daily alternate image a few days after Beta 1.
I fixed my system by booting the recovery mode with "nomodeset" appended to the grub boot command, and then ran the manual nvidia install shown in the known issues for http:// www.ubuntu. com/testing/ lucid/alpha2 - the bit about Jockey not supporting the Nvidia alternates system. I then rebooted and the nvidia kernel module failed to load, but the vesa fallback worked. I then reinstalled nvidia-common and it worked, fixing the nvidia driver.
Hope that helps as a workaround, I don't know if it will still work at this point.