.0.9.6-rc1 Install stuck at DB

I tried to find this in the forum - no hits.
I am installing v 0.9.6-rc1 and got as far as the DB
"Creating connection to the database: Database connection failed!"
The config.inc.php has the same into as used previously with v 0.9.5 and using the same user and password I have no trouble getting in to the DB with MySQL Administrator. The config.inc.php is set for Read so that is not the problem.
I’m stuck.
Thanks,
Hal D

On another try used the "edit DB" choice and the install completed ok. Nothing was changed in that case that wasn’t already in the config.inc.php file. So why did it not work until I changed the method of completing the install?
Hal D