errno 13 accessing my db : privileges problem ???

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I'm running a recent version of Mysql on SunOS.
when i try to access to a database, I receive a
errno 13 : cannot access database.
if I change my database's folder right to 744 (user is me), it's some kind of better and i get the following error message :
...
mysql> USE appov
Reading table information for completion of table and column names
You can turn off this feature to get a quicker startup with -A

Didn't find any fields in table 'events'
Didn't find any fields in table 'loadz'
Didn't find any fields in table 'login'
Didn't find any fields in table 'ovtresh'
Didn't find any fields in table 'polling'
Didn't find any fields in table 'polllist'
Database changed

What may I do to etablish a good connection (it was working last year )

Thanks !!!

JD Paris