I have not heard of this problem, but quite frankly, I have not paid much
attention to Vista in general. My opinion is that you should NOT eliminate
Vista. You may need it, especially if you encounter problems with installing
Ubuntu. That gives you an OS and some consistency.

Two possibilities exist. The first is, if you have the Ubuntu CD put it into
your drive inside Vista and see what happens. It will attempt to install Ubuntu
using the files on the CD, whereas wubi.exe as downloaded does a net
installation. You may get different results. The second possibility is that you
can try to install Ubuntu from the CD. This involves partitioning, but we can
step you through it. The worst case scenario is that it will give you Ubuntu
that does not work to your satisfaction and you will format over it and have an
empty partition to use as you want.