You shouldn't really be using unity notifications with GNOME anyway. GNOME has it's own notifications system. You need to use that.
The concept is that you either use:
Although there is a little crossover here and there, the messaging systems tend to be built into the compositor most of the time.
EDIT: this is not exactly an answer but it was too long for the comment, sorry. I had not realised I already posted one.
In short. There's not enough information to make it possible to help at the moment. It could be anything really.
Do you know how to get a stacktrace with gdb? It's worth getting one and posting it in a paste to here so people can take a look at the problem.
If you are not sure how to use gdb a quick check of the logs is to run:
/var/log | grep -rn "(EE)"
then try the same replacing
"(EE)" with with
failed should mean something useful comes up for one of these. Then it will be easier to answer the question.
You may also wish to check
synaptic package manager under '
broken' packages just in case something comes up there
It is still hard to tell without knowing more of the problem but, what it seems like is that you are still missing some sort of dependency. So, in that case try this:
sudo apt-get build-deps unity
and other unity related stuff you need (sorry I don't use unity so I would not know the usual list a person normally installs to complete the environment but at a guess I'd say there's an associated
display manager: things like that).