I'm using Joomla 1.5.15 and !Joomlacomment 4.0 RC1.

To reproduce the problem, you must have an SSL-capable site and in the Global Configuration set Server -> Force SSL to "Administrator Only." Next, go Components -> !Joomlacomment -> Manage Comments. Take a look at the URL's in the ContentItem column. Instead of valid URL's the URL's duplicate the domain like this:
https://www.domain.comhttps//www.domain.com/index.php?option=com_content&view=article&id=171&joscclean=1#josc1118
Obviously, a URL like that doesn't work. I also notice the Itemid isn't in the URL's in the ContentItem column. That's not essential, but it would be a nice addition.