Alas for some reason it makes Eclipse 3.6.2-1 crash when trying to render a tooltip.
Please, don't try to downgrade the XUl version yet, instead use the following workaround:
-Dorg.eclipse.swt.browser.UseWebKitGTK=trueto your eclipse.ini configuration file, at the bottom.
Afterwords just install the webkit package:
for window$ it's more complicated :S (as expected), guide.
For more info of the bug, visit the bug page.
Now just restart Eclipse ;) !
happy coding :) !!!.