In IE 6/7, editing blocked by overlaid "link box", and other IE problems

Hopefully I describe this adequately... let me know if you need screen shots or something.

I have two private wikis, one created back in April '07, and one created in December '07.

In the April wiki, I'm using Snakeskin as the skin. In the Dec wiki, I'm using Hyperreal.

No problems with anything in Firefox.

In the April wiki, I don't have any known issues (even if I change to Hyperreal).

In the Dec wiki, I have two main problems:
1. If I edit a page, when I click anywhere in WYSIWYG mode I get a transparent, bordered box overlaying the content, preventing me from clicking on any text. If I right click, I get a context menu with a single option: Remove Link. (If I do that, it removes all links on the page.) The cursor also becomes a "move" cursor (four arrows). This occurs in all themes.

2. I left the default yellow-background paragraph with edit instructions at the bottom of the page. In Hyperreal, the yellow-background extends to the entire page if the window is resized so that the Sidebar box causes the content to drop below it, but there is no horizontal scroll bar. (In other words, everything on the page has a yellow background.) When the sidebar is not movign the text, or when the horizontal scrollbar is visible, this is not a problem. This occurs in IE7/Vista and IE6/XP.