Themes not working in Eclipse

I have setup 4 machines with Eclipse and Vaadin, 2 Windows and 2 Mac’s. On two of the machines (1 Mac and 1 Windows) the theme is not being used by the internal Eclispe Browse. It does use the theme when I browse to the local Tomcat server using an External browser. What could be causing this?
Thank you

Hi Freddy, I can’t think up of anything that goes beyond “empty cache of IE”. I’m not aware that themes are browser-dependent. Good luck with it anyway - let us know when you found out!

I do not think the themes are the issue and the problem does not seem to be with IE (unless that is the browser uses internally on both Windows and Mac). It is like the browser in Eclipse is not reading the Style sheet at all. I was thinking it was a configuration issue, but I can not find anything in the preferences that point to that.