I just loaded a gif and a pdf, and IGB wasn't happy:

Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException
at com.affymetrix.igb.view.load.GeneralLoadUtils.loadAndDisplayAnnotations(GeneralLoadUtils.java:707)
at com.affymetrix.igb.view.load.GeneralLoadView.loadFeature(GeneralLoadView.java:316)
at com.affymetrix.igb.view.load.GeneralLoadView.loadFeatures(GeneralLoadView.java:303)
at com.affymetrix.igb.view.load.GeneralLoadView.loadWholeRangeFeatures(GeneralLoadView.java:298)
at com.affymetrix.igb.view.SeqGroupView.genericServerInit(SeqGroupView.java:605)
at com.affymetrix.igb.general.ServerList.fireServerInitEvent(ServerList.java:510)
at com.affymetrix.igb.view.load.GeneralLoadUtils.addChromosomesForUnknownGroup(GeneralLoadUtils.java:1172)
at com.affymetrix.igb.view.load.GeneralLoadUtils.openURI(GeneralLoadUtils.java:1157)
at com.affymetrix.igb.IGBServiceImpl.openURI(IGBServiceImpl.java:381)
at com.affymetrix.igb.shared.OpenURIAction.openURI(OpenURIAction.java:44)
at com.affymetrix.igb.action.AbstractLoadFileAction.loadFile(AbstractLoadFileAction.java:102)
at com.affymetrix.igb.action.AbstractLoadFileAction.actionPerformed(AbstractLoadFileAction.java:49)
at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:2028)
at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2351)
at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:387)
at javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:242)
at javax.swing.AbstractButton.doClick(AbstractButton.java:389)
at com.apple.laf.ScreenMenuItem.actionPerformed(ScreenMenuItem.java:95)
at java.awt.MenuItem.processActionEvent(MenuItem.java:627)
at java.awt.MenuItem.processEvent(MenuItem.java:586)
at java.awt.MenuComponent.dispatchEventImpl(MenuComponent.java:337)
at java.awt.MenuComponent.dispatchEvent(MenuComponent.java:325)
at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:682)
at java.awt.EventQueue.access$000(EventQueue.java:85)
at java.awt.EventQueue$1.run(EventQueue.java:638)
at java.awt.EventQueue$1.run(EventQueue.java:636)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.AccessControlContext$1.doIntersectionPrivilege(AccessControlContext.java:87)
at java.security.AccessControlContext$1.doIntersectionPrivilege(AccessControlContext.java:98)
at java.awt.EventQueue$2.run(EventQueue.java:652)
at java.awt.EventQueue$2.run(EventQueue.java:650)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.AccessControlContext$1.doIntersectionPrivilege(AccessControlContext.java:87)
at java.awt.EventQueue.dispatchEvent(EventQueue.java:649)
at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:296)
at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:211)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:201)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:196)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:188)
at java.awt.EventDispatchThread.run(EventDispatchThread.java:122)