Permissions are 755 (already tried 777)
There is a GD module installed

the website is: www.microfama.com.br (there is a tag Simple Image Gallery start/end to show where is the gallery that is not working properly).

Read a lot of entries in the forum and did not found any solution for this problem.

Any help please?

Gave up.
Just installed sigplus and it works fine in the first try.