This is strange. Can you please send us the .aip (project file) which replicates this issue to support at advancedinstaller dot com so we can test it? Also, please specify us which resolution do you use on your monitor and if you are using a custom DPI size.
It isn't project-specific -- it happens with all of my projects. My monitor resolution is 1920x1080 and I do not use a custom DPI size. I am on Windows 7.
I think it has something to do with having actions shared in both sequences and using the "hidden" upgrade options.
I've tested again your scenario, but to no avail. I cannot replicate the display issue. If you could iterate a step by step test case which we can follow to replicate the issue this will be great.
Also, please try to isolate the issue in a sample project and sent it us so we can investigate on our side.
Thanks for investigating. I'm not sure that I can create steps to reliably reproduce it -- it seems to happen somewhat randomly after using the custom actions page for awhile. If I can figure out how to make it happen, I'll let you know. Maybe it's just something bizarre with my machine.