Kontact on Windows - Problems with deleting

[Jochen May]

Hallo!

I use know for a while the actual Kontact Client for Windows without any 
bigger problems. Only one thing is a little bit strange:

When i delete an mail, the mail disapear from the mail-folder. But on the next 
sync, the mail is putted back in the mail folder. I can delete the mail again 
and after the next sync, the mail is back in the folder. Even if i press 
the right mouse button or click and drop the mail to move it to the trash, it
´s the same. It will be back every time...
The funny thing is that the mail disappear from the folder and show up in the 
trash folder. And after the next sync, the mail ist still in the trash folder 
and in the normal folder.

If i move an mail to any other folder, no matter if it´s via right mouse 
button or click and drop, the mail is moved without any problems... 

The OS is Windows 7 Professional

Greetings
Jochen May