HTC Imagio, calendar not working
 

I install a couple of 3rd party programs, Iambic Agendus Pro and Pocket Informant, with both of them, I couldn't add a calendar appointment, no error message. I uninstalled both of them and using the built in calendar, I still can't add an appointment, error, (An unexpected error has occurred in this program). I called Verizon, but they couldn't help, I'm sure I need to work in the registery, I have a program for that, but not sure what to do.
Thanks for any help.
Rocky