Reported by Chris:

Confluence has a bug (which I originally thought was in the UWC) in the way it parses wiki markup. Originally discovered while trying to import a mediawiki instance into confluence I have found that the wiki markup parser fails to render images under a given circumstance.

This link points to my comments on the UWC forum about it
http://forums.atlassian.com/message.jspa?messageID=257346941#257346941

Essentially the problem is if you follow some wikimarkup with a non whitespace character the markup is escaped and the code not rendered.

so

!image.jpg|align=right!Bla Bla Bla

fails to render and the markup is changed to

\!image.jpg\|align=right\!Bla Bla Bla

Thus inline images fail, Other markup may fail due to this but I haven't tested it.