Crashes while testing and working User Interface same time

Hi everyone,
excuse me if i'm not very polite, it's my first time in this forum and i don't know rules and uses, and please, excuse my english too

Here is my problem, i have changed to Windows 7, and while testing some WS if i start working with the user interface for other pourposes my SOAP-UI always crashes, and if i open a Test case this takes about a minut to be opened, this is when i work with the exe, if instead of this i use the BAT none of this problems happens.

Anyone knows if it's an existing bug or just a configuration OS trouble? I'm working with SOAP.-UI 4.5.1 and a Windows 7 with a jre 1.7.0_09 installed on it (i have seen than SOAP-UI uses an included 1.7.0_07-b11 internally)

The stack trace in error.log is:

Exception in thread "AWT-EventQueue-0" java.lang.ArithmeticException: / by zero
at org.fife.ui.rsyntaxtextarea.SyntaxView.viewToModel(SyntaxView.java:816)
at javax.swing.plaf.basic.BasicTextUI$RootView.viewToModel(BasicTextUI.java:1552)
at javax.swing.plaf.basic.BasicTextUI.viewToModel(BasicTextUI.java:1101)
at javax.swing.plaf.basic.BasicTextUI.viewToModel(BasicTextUI.java:1074)
at javax.swing.text.JTextComponent.viewToModel(JTextComponent.java:1446)
at org.fife.ui.rtextarea.FoldIndicator.findOpenFoldClosestTo(FoldIndicator.java:163)
at org.fife.ui.rtextarea.FoldIndicator.access$300(FoldIndicator.java:60)
at org.fife.ui.rtextarea.FoldIndicator$Listener.mouseMoved(FoldIndicator.java:671)
at java.awt.AWTEventMulticaster.mouseMoved(AWTEventMulticaster.java:329)
at java.awt.Component.processMouseMotionEvent(Component.java:6550)
at javax.swing.JComponent.processMouseMotionEvent(JComponent.java:3339)
at java.awt.Component.processEvent(Component.java:6274)
at java.awt.Container.processEvent(Container.java:2229)
at java.awt.Component.dispatchEventImpl(Component.java:4861)
at java.awt.Container.dispatchEventImpl(Container.java:2287)
at java.awt.Component.dispatchEvent(Component.java:4687)
at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4832)
at java.awt.LightweightDispatcher.processMouseEvent(Container.java:4505)
at java.awt.LightweightDispatcher.dispatchEvent(Container.java:4422)
at java.awt.Container.dispatchEventImpl(Container.java:2273)
at java.awt.Window.dispatchEventImpl(Window.java:2719)
at java.awt.Component.dispatchEvent(Component.java:4687)
at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:723)
at java.awt.EventQueue.access$200(EventQueue.java:103)
at java.awt.EventQueue$3.run(EventQueue.java:682)
at java.awt.EventQueue$3.run(EventQueue.java:680)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:87)
at java.awt.EventQueue$4.run(EventQueue.java:696)
at java.awt.EventQueue$4.run(EventQueue.java:694)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76)
at java.awt.EventQueue.dispatchEvent(EventQueue.java:693)
at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:244)
at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:163)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:151)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:147)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:139)
at java.awt.EventDispatchThread.run(EventDispatchThread.java:97)

I can work correctly with the BAT, but until i noticed this, i wasted lots of time, i'll hope this works to solve the same for other people.