Hi,
if after writing \cite{ i press I don't get the windows described
in the help file.
I get two windows: the first one, named Quickfix, where, for each row,
is shown only the first row of each bibtex item; in the second window
is shown the relative file .bib.
In addition, while the cursor is in
I'm not sure if this can help, but did you try :
1. Installing vim in a folder without any space in it (like "c:\vim",
unlinke "c:\program files\vim")
2. Installing Python (also in a folder without any space)
This solved a problem I had with the completion of \ref (not \cite), maybe
that can help