You do not have sufficient permissions to access this page.

Hello!

I have multiple blogs in one database.
The sites are indexed like this:

http://www.puurnatuurspanje.com
http://www.puurnatuurspanje.com/english/
http://www.puurnatuurspanje.com/spanish/
etc etc.

Everything is fine because I used prefixes for the tables for the different languages.
But, and here comes the problem:

When I try to login at the spanish website I got this error:

You do not have sufficient permissions to access this page.

I got this error after upgrading all the blogs to 2.7.
The other languages work fine though!

Can someone please help me out how to fix this problem?!

GREAT thanks!

Vincent