Crash on start up of SoapUI v.4.5.1

Hi, I have a small problem with SoapUI 4.5.1 and newer versions as well.
Please note that these issue appeared literally over night (I think after a Java update but I'm not sure), one day the application run without any problems and the next day it crashed on start up with the following error:

java.lang.ExceptionInInitializerError
at com.eviware.soapui.DefaultSoapUICore.initSettings(DefaultSoapUICore.java:405)
at com.eviware.soapui.SwingSoapUICore.initSettings(SwingSoapUICore.java:118)
at com.eviware.soapui.DefaultSoapUICore.init(DefaultSoapUICore.java:146)
at com.eviware.soapui.StandaloneSoapUICore.<init>(StandaloneSoapUICore.java:38)
at com.eviware.soapui.SoapUI$SoapUIRunner.run(SoapUI.java:662)
at com.eviware.soapui.SoapUI.main(SoapUI.java:761)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at com.exe4j.runtime.LauncherEngine.launch(Unknown Source)
at com.exe4j.runtime.WinLauncher.main(Unknown Source)
Caused by: java.lang.IllegalArgumentException: The maximum must be greater than 0.
at org.apache.http.conn.params.ConnPerRouteBean.setDefaultMaxPerRoute(ConnPerRouteBean.java:81)
at org.apache.http.impl.conn.tsccm.ThreadSafeClientConnManager.setDefaultMaxPerRoute(ThreadSafeClientConnManager.java:349)
at com.eviware.soapui.impl.wsdl.support.http.HttpClientSupport$Helper.<init>(HttpClientSupport.java:211)
at com.eviware.soapui.impl.wsdl.support.http.HttpClientSupport.<clinit>(HttpClientSupport.java:64)
... 12 more

I have tried the below steps without any success:
- install/uninstall JDK 6
- install/uninstall SoapUI and restart the computer
- use CCleaner to clear register of SoapUI related files

I tried with newer and older SoapUI versions but i get the same error message.
Any ideas on how to resolve the issue?