I don't think it's the switch to 4.1. In fact, I've recently upgraded to CS3 (4.1) and noticed that the multiple link bug is gone! In terms of the images, I'd investigate the image properties to see if some bit of code is "lingering" in the background after removing the link (view source code in the browser). I assume you're right-clicking the image to edit the properties...you can do the same thing to edit the link without using the buttons at the top. Just some ideas.............
I'm having a similar problem. A web site that was working fine with Contribute is now not allowing the addition of ANY links (pages or documents). Won't allow the action even though you can still edit the content of the page just fine. The problem is in Contribute 3 & 4, Mac & PC. There is a work around of copying and pasting an existing link and then editing it. But that's not the kind of solution I like to tell clients (and not one they like to hear).
Hope Adobe will chime in with a solution.
I'm receiving the same error message when I try to delete an image/link that I inserted through HTML code. The image is at the bottom of my page, not sure if that is the "region of the page" the error message is referring to, but it won't let me delete it now even though it let me originally insert it there!
I had the problem with links that contained an escaped HTML character (like & – etc) in the link text, not in the url itself. When I replaced these with a regular character I was able to publish the links without a problem.
So this works:
<a href="link.html">this is my link - june 2010</a>
And this doesn't:
<a href="link.thml">this is my link – june 2010</a>
Which is kind of weird, of course. I hope this helps.
Since I've been creating pages and content with this method for years and have only had a problem in the last month, I don't really feel like this has been "solved". I certainly don't want to go back and edit all my pages using php for site organization but at least this will allow the client to make edits for now.