GRAMPS freezes and crashes
There have been multiple reports of long freezes and crashes of GRAMPS when refreshing the people view, e.g. after editing a person or changing the Name Display Format. They are related to the use of GNOME Assistive Technologies (ATK/GAIL). If you experience similar problems try going into System -> Preferences -> Assistive Technologies, unchecking "Enable assistive technologies" and logging out and in again.
GRAMPS runs out of locks
With a large database, GRAMPS can "run out of available locks". See bug report below.
Cannot import Media with non-ASCII characters on filename
If Python returns a codec/UTF8 warning and this file was pasted from an external support (CD, HD, USB key), maybe filename has been corrupted ! It seems correct on screen but not on command line. Your OS was not able to properly set the encoding used on your external support.
Make a copy of your file from your disk to your disk. If the accentued characters will be a "?", then fix the filename by setting the correct character. Now you will be able to import this file into Gramps !