MySQL read-only error

I have a problem with MySql

I have SUSE 7.2 with Apache, php4 as a module and mysql.

when I try to modify something in my database and the response is always:

"Table xxx is read-only"

even in the console.

I've tried to flush tables and don't work.

I've chmod'ed the files to 777!! and don't work.

Can anybody help me please??

Are you using compresses tables in mysql?

MySQL's most common problem is table corruption, so you may want to read the MySQL manual about myisamcheck

Thank's for your help.

My table is not compressed.

I tried do check it with myisamchk and I saw that the user table in mysql db seemed to be open by another user when it was closed.

In spite of this error, I even can't insert or delete any register in my db.

I only can modify it if I start the mysql daemon with:

mysqld -u root --skip-grant-table

Any suggestion?