Hello,

I have the same problems as Victor: I upgraded to 3.5.2-2ubuntu2 and Eclipse freezes when loading the workspace (more exactly, the freeze occurs after all the initializations and initial compilation of projects have completed). 
I don't use Aptana, it's a regular Eclipse with a few plugins (AspectJ with weaving enabled, P4, WTP, TPTP, Data modeling, Mylin, IAM).

Here is the stack trace for the thread that is hanging:
 
java.lang.Thread.State: RUNNABLE
	at org.eclipse.swt.internal.mozilla.XPCOM._Call(Native Method)
	at org.eclipse.swt.internal.mozilla.XPCOM.Call(XPCOM.java:540)
	at org.eclipse.swt.browser.Mozilla.create(Mozilla.java:588)
	at org.eclipse.swt.browser.Browser.<init>(Browser.java:119)
	at org.eclipse.jface.internal.text.html.BrowserInformationControl.isAvailable(BrowserInformationControl.java:87)
	at org.eclipse.jdt.internal.ui.text.java.hover.JavadocHover$HoverControlCreator.doCreateInformationControl(JavadocHover.java:342)
	at org.eclipse.jface.text.AbstractReusableInformationControlCreator.createInformationControl(AbstractReusableInformationControlCreator.java:45)
	at org.eclipse.jface.text.AbstractInformationControlManager.getInformationControl(AbstractInformationControlManager.java:808)
	at org.eclipse.jface.text.AbstractInformationControlManager.internalShowInformationControl(AbstractInformationControlManager.java:1157)
	at org.eclipse.jface.text.AbstractInformationControlManager.presentInformation(AbstractInformationControlManager.java:1139)
	at org.eclipse.jface.text.AbstractHoverInformationControlManager.presentInformation(AbstractHoverInformationControlManager.java:902)
	at org.eclipse.jface.text.TextViewerHoverManager.doPresentInformation(TextViewerHoverManager.java:243)
	at org.eclipse.jface.text.TextViewerHoverManager$5.run(TextViewerHoverManager.java:233)
	at org.eclipse.swt.widgets.RunnableLock.run(RunnableLock.java:35)
	at org.eclipse.swt.widgets.Synchronizer.runAsyncMessages(Synchronizer.java:134)
	- locked <0x00007f0a6d3aef58> (a org.eclipse.swt.widgets.RunnableLock)
	at org.eclipse.swt.widgets.Display.runAsyncMessages(Display.java:3468)
	at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:3115)
	at org.eclipse.ui.internal.Workbench.runEventLoop(Workbench.java:2405)
	at org.eclipse.ui.internal.Workbench.runUI(Workbench.java:2369)
	at org.eclipse.ui.internal.Workbench.access$4(Workbench.java:2221)
	at org.eclipse.ui.internal.Workbench$5.run(Workbench.java:500)
	at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:332)
	at org.eclipse.ui.internal.Workbench.createAndRunWorkbench(Workbench.java:493)
	at org.eclipse.ui.PlatformUI.createAndRunWorkbench(PlatformUI.java:149)
	at org.eclipse.ui.internal.ide.application.IDEApplication.start(IDEApplication.java:113)
	at org.eclipse.equinox.internal.app.EclipseAppHandle.run(EclipseAppHandle.java:194)
	at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.runApplication(EclipseAppLauncher.java:110)
	at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.start(EclipseAppLauncher.java:79)
	at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:368)
	at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:179)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
	at java.lang.reflect.Method.invoke(Method.java:597)
	at org.eclipse.equinox.launcher.Main.invokeFramework(Main.java:559)
	at org.eclipse.equinox.launcher.Main.basicRun(Main.java:514)
	at org.eclipse.equinox.launcher.Main.run(Main.java:1311)
	at org.eclipse.equinox.launcher.Main.main(Main.java:1287)

If I add -Dorg.eclipse.swt.browser.XULRunnerPath=/usr/lib/xulrunner-1.9.2 to /etc/eclipse.ini, then it seems to work, so far.

Thanks, Ludovic