Recently active problems in PBwiki tagged with editing

What is the purpose of the sidebar on my wiki? I've never used a wiki before. How do I change the sidebar?

I have a large table on my wiki. If I edit the page and then save without making changes it adds an extra blank line to every cell in the table.
Specifically, looking at the HTML, it adds
 
This website doesn't seem to like HTML. Let me repeat that, it adds
<p>p&&hash;160<p>

Whoops, it already has been reported:
http://getsatisfaction.com/pbwiki/top...

When I try to attach a file, it erases my entire page. How do I prevent this?

Some of my students don't have the link option so they can't make their own pages within our class wiki. I may have invited them into the wiki using the wrong category. Also, som of them are prompted to give secret code before they can edit a page. What I'd like for them is to have the simplest access and I want them to be able to write their own pages and comment or write pages with others in the group.

What did I do wrong? What can I do to fix it.

I apologize if this is a duplicate!!! This Video hangs at Finish.