I have a problem with the advanced search. The "normal" search engine does function well, but the advanced search does not. The connectors "and" and "or" are not working, I always get the error that no links are found. Even with the "+" and "-" it is not working.

I have the right weights in the links table and I did a reindex. The search engine also can find the links, but the connectors are not working. What do I make wrong? How to solve the problem? Thanks for your help...