here is a simple hint how to solve IMEI changes not appearing on newly installed v5.6
1. uninstall the old mxkey software.
2. delete everything inside C:\mobileEx\3.2\
NOTE: do not delete the folder 3.2 just the files inside it.
3. click start menu => RUN => regedit => HKEY_CURRENT_USER\Software\mobileEx
right click on the mobileEx then delete. look below: 
4. click start menu => RUN => regedit => HKEY_LOCAL_MACHINE\SOFTWARE\mobileEx
right click on the mobileEx then delete. look below: 
5. Now install the latest version of your MXkey..
below you can see BEFORE and AFTER the guide was made.
Before: 
After: 
hopes this helps other having a problem about a clean installing of their MXkey.
BR
freddy
www.gsmph.com