I just ran into this and the root cause was that the .ldf and .mdf it was trying to create already existed, because an earlier copy of the database had been renamed in the SQL IDE, which does not rename ldf/mdf on file level:- Create db named db_name...
I don't suppose you (or anyone else) ever came across a separate downloadable ISUS.msm for 4.5? We have an older version of Installshield and somehow the much newer 4.5 version got into the last release. Of course the machine that had Installshield D...