It seems that when the Java2 plug-in is used (Firefox, Chrome), the keyboard does not always works. Sometimes, I have to click on the applet several times, or worst, have to take the browser out-of-focus and then re-focus in order to for keyboard inputs to be properly captured. Just wondering if anyone is having similar problems.
This sounds like an issue with the Apple Java Plugin and not something on the LWJGL side. Mainly because LWJGL doesn't do anything special with the focus handling other use the standard AWT Canvas. It is however likely that the issue has already been fixed in the latest developer preview of Apple Java (the next version Java Update 6) since Apple implemented some bug fixes around this area.