Hey Jim-
Can you put up here the conditional logic that is failing for you? If you can copy and paste it from your own project, I might be able to find the problem. Sometimes something seemingly insignificant can cause the entire thing not to work.
Case in point, I just helped another reader figure out how to get the CSS Adapaters to work on his project. The major problem? His CSS Class referenced AspNet-Gridview instead of AspNet-GridView. If you didn't immediately see the difference, the v isn't capitalized in his example but it is in the divs rendered by the adapters. And CSS is case-sensitive. So, when the browser was looking for the style rules for AspNet-GridView it couldn't find any and so it didn't apply any style.
Anyway, it is hopefully something as simple as that that you might spend all day looking at and not see but a fresh set of eyes might spot immediately. If you can post the code you are using, I can download it here and run it and see what I see.
Thanks!
-Jacob
Jacob J. Sanford
Author of
Professional ASP.NET 2.0 Design: CSS, Themes, and Master Pages
Co-author of
Professional SharePoint 2007 Design