I have never dual booted, I`m sorry I don`t know. I normally just install over the whole hard drive.
However, that is a different question, as is the problem with Ubuntu not booting, (which, I`m sorry to say I don`t know about either). My point is that you need to start a new thread. Something like -

"Can`t boot ubuntu [ 24.924478] ..MP-BIOS bug: 8254 timer not connected to I0-APIC"

to see if anyone can fix that problem. If not then -
How to reinstall ubuntu without affecting Vista partition

It`s no good asking those questions in a thread about wireless things `cause the guys who can help you with your new problem might not read it - if you get what I mean.