Sorry, I answered a bit too quickly to acrylian: I tried to modify the query from the administration panel, and it didn't work; now, I understand what you mean, and just made the modification directly in the `.alb` file.
The search was not so unusual, and I had done the same several times before: I was just looking for all the pictures having the [b]star[/b] in order to group them in a dynamic album called [b]star[/b] too.
Or could the problem be related to the fact that specific album had already existed in the past? But I had deleted it beforehand from the administration panel...
Another idea: I've set the access rights to the `/albums` directory to 700, and the dynamic albums to 604 (I don't remember if I created them before I changed the main folder rights or no) so no visitor can access the original pictures without being watermarked; any possible relation?