Sorry to hear you are having issues. Don't not see any other report on this issue before. Need more information.
1) Windows version, please use Winver.exe for full Windows version numbers.
2) Curtains version installed.
3) Is the issue happen on any Curtains style? or only on some specific styles?
4) A video of the issue happening would help us understand it much better. Grab a video and upload it to sharing site and share its link here.
Stardock Community Assistant.