I use Geany 0.19, GTK+ 2.16.6, GLib 2.20.5 (French_France.1252) on windows.
I have some troubleshootig with some dialog as color chooser or open / save dialogs (windows style)
I don't know how to describe this, but maybe an image can more so see geanyLag.png
this troubleshooting is maybe from gtk but ... you will see if you can change something.
Thanks for all