I've just installed a new Joomla 3.2.3 without any problems.

After loggin out and in again in the adminstrator area, I can see the top menu buttons disappeared!

I have re-installed Joomla again using the extensions manager but it didn't work out. Now, I have uploaded all the files again using FTP. It did not work either.

I know other users experienced the same problem, can anyone share some ideas how to fix this problem?