Upgrade to CRM 5.0

Hi All...

I came across some threads on this issue but i need some help. We have upgraded from CRM 4.0 to CRM 5.0 When am trying to execute the t-code CRMD_BUS2000111, am getting the dump CL_EXITHANDLER======CP. it is not working for some other transactions too.

i wanted to debug the issue and i tried to open the class and wanted to put a break point in the method GET_INSTANCE and i get a short dump which says MESSAGE_TYPE_X in the function 'AC_FLUSH_CALL'. As per the threads i read in SDN i found it might be an issue of the SAP GUI and the kernel patch difference. But am using SAP GUI 6.40 and kernel patch is 75.

Can any of you please guide me how to solve this issue?

Any help would be appreciated with points!