Yes, I see what you mean. This problem and others appear to be fixed in Tiki 1.9.8, which is coming soon. How does the bluegreen theme work for you at this site (which is using a 1.9.8 CVS version of bluegreen.css)? You could try using that file and see if the CSS update alone will solve the problem at your site. Or wait until the 1.9.8 release and then update. There are many fixes and enhancements in the coming release.