It's possible that the Eclipse XML/HTML editor got its brains scrambled. That's fairly easy to do. Generally restarting Eclipse clears stuff like that, although a refresh is a good idea, too.
For actual tags (not scriptlets), you can attach an XML catalog where the tags' DOCTYPES resolve to a syntactical reference (DOCTYPE or XML schema) in the catalog. I do this whenever I think I have too much hair and need an excuse to rip some out.
Finally, check to see that you're using the right editor when editing the JSPs (you can right-click on the file in the Navigator view to select an editor). I'm not sure that the strict XML editor would like scriptlets at all.
Then again, neither does Bear. His position is that code belongs in Java classes, not on JSPs, and most experts agree. Scriptlets are mostly just left over from when J2EE was less powerful.
An IDE is no substitute for an Intelligent Developer.