Problems with seamless mode since update

[rfemali]

I have a Mageia 5 host and a Win 7 guest on dual monitors. Since I got the VirtualBox update to 5.1.18, the guest will boot in seamless mode (most of time) with no issues, but if I switch out of seamless mode and try to go back, the guest is moved to only screen 2. Any help would be appreciated.