mangelo123,
Sorry that you are running into this issue.
Can you give me some details to investigate further?
1) Could you go to Help > About and mention exactly what version of MyEclipse you are using? Please copy the build Id from there into this thread.
2) If you keep the Progress view open, are there Jobs that you see running while you are editing your facelets page?
3) All Facelets/XHTML pages need to be opened with the non-default MyEclipse JSF/Facelets Designer. Open Facelets/XHTML pages by using the open-with menu to select the MyEclipse JSF/Facelets Designer. Check if the issue still persists.
4) Can you replace the vmargs section in your ini file with the snippet below and see if that improves performance?
-vmargs
-Xmx768m
-XX:MaxPermSize=256m
-XX:ReservedCodeCacheSize=128m
5) Do you have a large number of resources in your project or a large number of resources (JS, JSP, HTML) files in your workspace?
6) Can you switch to a new workspace and check if the issue perists?