It happens often, that older movies are not named according to IMDB - I mean: The matrix reloaded, not The Matrix Reloaded - I am trying to rename all I see, but it is too much for one person - it is good idea to rename them according to IMDB - or not?

Yes, this was already mentionned in the comments of one of the movies:
http://www.imcdb.org/movie.php?id=51604
It is due to the old site data. The best way to write titles as written on IMDB, i.e. respecting each language conventions (cf URL above).