Did you find a solution to this? I have very similar problem with similar symptoms. I logged into the GotomyPC Host and dragged a file across to the remote desktop after which I apparently had no screen update. I tried ctl alt del and launch Task Manager but saw nothing happening. I followed the advice above and logged out and back in again to find that all the commands I had entered had been successful but the remote screen had not been updated. This looks like a repeatable problem and obviously recoverable if annoying.
@bijouorme Sorry about that.
What operating system is the Host computer running?
When was the last time this Host was rebooted?
Can you also confirm the GoToMyPC build installed there?