I am trying to remove YouMail with BBDesktop 4.7 Application Loader.
When I click on YouMail to clear the check, the check mark reappears.
I have closed my account with YouMail.
Have you tried going to Options/Advanced Options/Applications on your berry and deleting it there?
You may have to do a battery pull after that.
Also, there is some info in this thread about it: http://forums.crackberry.com/f52/remove-youmail-209943/