Work for another a few days: new errors and punishment by "Kernel"

When I went forward setting up the first VM, a new error came out that the VM IMG and not be connected to xen server. I went back to check each step I did spending a few hours to figure out the issue.
The reason is that the xen has not a protocol or port for any new VM, so there must be something wrong in the server level.
Again, in the /etc/xen/xend-config.sxp, #(xend-unix-server yes) was not working because of #, so I removed the # infront of it.
Try again, still not working. Try some other way, I found that #(xend-http-server no). This may be what I want.
Change it to (xend-http-server yes).
Then I worked for a while until I restarted the computer. When I rebooted the computer, I found that I cannot go into Ubuntu with Xen kernel. I went into the recovery mode for Xen, neither did it work. So I went into noraml version of Ubuntu, neither did it work!!! Then, I went into the recovery mode of it, and spent quite a long time to figure out what happened to the computer.Finally, I found that in the menu.lst the names of kernels have changed!!!!
Oops! I upgraded the Linux kernel from 3.0.0.12 to 3.0.0.16, every thing has changed, and Xen kernel was not recognized any more. Every thing went in ruins....
Yap, I need repeat my work again on this computer from installing Linux to the end of setting up Xen...
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After quite a few hours, I finished the work and I do hate the kernel!