Phpbb / could not connect to database

i have had problems with setting up anything using mysql lately. i had a phpbb set up and running well with no problems until tonight when i accidentally uploaded the config file for something else over it’s config file. i ran the set-up again and it tells me that it could not connect to the database.

as far as i can tell, all the information is correct. it ran fine before, but i cannot for the life of me get it running now!

i also have been able to get mt and pmachine running because of the same type of errors. i can log into the databases using my usernames/passwords without any problems, but i can’t get any software to run!

i am frustrated to no end. can anybody help?