Blank page when csv-export

I'm trying to export categories to a csv-file, and the process starts but after aprox 10 sec, it leaves a blank page, not even "save as" appears.
Is it possible that my categoriestables are to big?
ls_categories = 3978 records, lc_categories_info = 7956 records.

Any suggestions is welcome

Regards
Peter
10 second should not be a timeout. There could be a RAM issue. Can you see if anything was logged in logs/errors.log ?
No there is nothing in the errorlog

Regards
Peter