Recently active problems in PBwiki tagged with files

I've tried to upload Hot Potatoes files (.htm) but I keep getting the message "File uploads are temporarily offline: Your IP address has been temporarily suspended because PBwiki's automated spam filter flagged recent activity. We're sorry for any inconvenience."

The main reason for my wiki is to have others working on the same topic able to edit and add to documents that I have uploaded. The problem is that when they have made their changes, the revised file is not what is on the wiki - that file remains unchanged.

It seems the only answer is to have folks make their changes and then upload the file again. This clogs thing up and would be confusing if the changes are not tracked somehow.