The only gripe I had was with its embedded rich text editor which uses TinyMCE. I’m using Firefox 1.5 and this rich text editor kept on replacing “src” with “xsrc” on my code snippets. It’s a problem because users like to copy paste sample codes. At the end I just set Wiki Markup as my default edit view.
After a quick sleuthing around, I found out that some pages in Confluence documentation page suffer the same problem (1, 2), WordPress.org user also had a similar problem. However, I couldn’t find any related bug in Confluence issue tracker and TinyMCE bug tracker. Briefly looked at tiny_mce.js, I think the problem could be at TinyMCE.prototype.fixGeckoBaseHREFBug function.