This is because the including JSP is not changed.
This is a FAQ around these parts; the answer is that this is generally not a good design because you must touch every JSP that includes it in order for the app server to know it needs to recompile them.
WSAD, as a developer tool, is a bit smarter than an app server at dependency tracking.
In WAS, the answer is to do a complete uninstall and reinstall -- making sure to regen the http server plugin and stop/start the app server after each step.
