I also have this problem with the installing Ubuntu 11.04 on my computer with wubi.
On around tens of times I tried to install, only 2 times the error did not happen. I do not know why. Same as Soybean, my computer works well and I have tried disk tests. This computer can install Ubuntu 9.10, 10.04 and 10.10 normally without any problems. This is the first time I get this problem. However, I still winder why 2 times the installation is done normally.
This error happened to me the first time and it is quite confusing while trying to install the new Ubuntu.
I also have this problem with the installing Ubuntu 11.04 on my computer with wubi.
On around tens of times I tried to install, only 2 times the error did not happen. I do not know why. Same as Soybean, my computer works well and I have tried disk tests. This computer can install Ubuntu 9.10, 10.04 and 10.10 normally without any problems. This is the first time I get this problem. However, I still winder why 2 times the installation is done normally.
This error happened to me the first time and it is quite confusing while trying to install the new Ubuntu.