my english is bad... Reproducible: Always
Shortly after the 3.0 release, the "bended lines" bug on windows was fixed. Can you try the windows builds in this kickstarter update post? The download links are at the bottom: https://www.kickstarter.com/projects/krita/krita-2016-lets-make-text-and-vector-art-awesome/posts/1594853 Is the problem fixed?
I'm sorry, but this report does not offer enough information to work on. I am going to have to close it.