I'm having a problem loading Eclipise in 12.04. I loaded the error log and this was inside:

!SESSION 2012-09-03 16:52:09.742 -----------------------------------------------
eclipse.buildId=I20110613-1736
java.version=1.7.0_07
java.vendor=Oracle Corporation
BootLoader constants: OS=linux, ARCH=x86_64, WS=gtk, NL=en_GB
Command-line arguments:  -os linux -ws gtk -arch x86_64

!ENTRY org.eclipse.osgi 4 0 2012-09-03 16:52:11.317
!MESSAGE Application error
!STACK 1
java.lang.UnsatisfiedLinkError: Could not load SWT library. Reasons: 
    no swt-gtk-3740 in java.library.path
    no swt-gtk in java.library.path
    Can't load library: /home/marcel/.swt/lib/linux/x86_64/libswt-gtk-3740.so
    Can't load library: /home/marcel/.swt/lib/linux/x86_64/libswt-gtk.so

    at org.eclipse.swt.internal.Library.loadLibrary(Library.java:285)
    at org.eclipse.swt.internal.Library.loadLibrary(Library.java:194)
    at org.eclipse.swt.internal.C.<clinit>(C.java:21)
    at org.eclipse.swt.internal.Converter.wcsToMbcs(Converter.java:63)
    at org.eclipse.swt.internal.Converter.wcsToMbcs(Converter.java:54)
    at org.eclipse.swt.widgets.Display.<clinit>(Display.java:132)
    at org.eclipse.ui.internal.Workbench.createDisplay(Workbench.java:695)
    at org.eclipse.ui.PlatformUI.createDisplay(PlatformUI.java:161)
    at org.eclipse.ui.internal.ide.application.IDEApplication.createDisplay(IDEApplication.java:153)
    at org.eclipse.ui.internal.ide.application.IDEApplication.start(IDEApplication.java:95)
    at org.eclipse.equinox.internal.app.EclipseAppHandle.run(EclipseAppHandle.java:196)
    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:344)
    at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:179)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
    at java.lang.reflect.Method.invoke(Unknown Source)
    at org.eclipse.equinox.launcher.Main.invokeFramework(Main.java:622)
    at org.eclipse.equinox.launcher.Main.basicRun(Main.java:577)
    at org.eclipse.equinox.launcher.Main.run(Main.java:1410)
    at org.eclipse.equinox.launcher.Main.main(Main.java:1386)

I had openJDK installed and to remove and replace with Oracle Java to install Aptana Studio.

This thread explains it all.

So now reinstalled OpenJDK, this might give some insight to the problem?