Mail message window scrolling in full screen

[BulkHedd]

Usually when I have the Mail app full screen, scrolling on the right pane is very slow and sluggish. The left pane (messages list) scrolls fine. If I switch out of full-screen mode everything scrolls fine.

Usually if I relaunch Mail it will scroll fine in full-screen mode at first but soon gets sluggish again.

I never had this problem with Mavericks. I know my MacBook Pro is old (2010) but I don't see any scrolling issues anywhere else.

Has anyone else experienced this?

 

[BulkHedd]

I'm also having the problem in Safari on the left-hand bookmarks pane. Sometimes it just won't scroll at all. I can usually grab the scroll bar (when it appears) and I can scroll up and down with it fine.

It just seems to be a problem when using the trackpad and even then not always.