virtualbox.org

I installed Kubuntu 14.04 on virtual box on my Window machine. Recently I upgraded to 5.0.20 from 5.0.16 and experienced some weird problem with my dual monitor. The issue is kubuntu cannot remember my monitor configuration any more. Every time I reboot my VM, both of my monitors will display the same contents (clone mode), I have to manually change the configuration again so that they display independent contents. However, my old configuration worked until 5.0.16. And I experienced the lost configuration problem on both 5.0.18 and 5.0.20.

Any suggestions?

These kinds of problems that are reproducible should be reported to bugtracker.
It would also help if you can post the ticket number here so other can see the progress, add information, or see the final results.