In detail: I can untag each file with space or by clicking the tag box but after I change the folder and come back it's tagged again.

Here is what I did: I set "clear tagged file list" to "on exit". I browsed to some folders and tagged files. Then I went to the tag-category and assigned a category to all tagged files (via View -> Set Category) and then I untagged all files. I can't reproduce the bug though.
Is this a know issue? And is there a workaround?
/edit:
Seems to be reproducable but not 100%. I can go into more detail if it's not known already.