Since JDK8 b89 I get rendering issues in custom controls. I have created a little video of the behavior in b89 and how it was in b88. You can find the video here
https://www.youtube.com/watch?v=P0OSnRi4nls
It might be related to the sizing problems on OS X Retina Macs that occurs since b87 but I'm not sure.
To be able to reproduce the problem I've created a little demo that you could find here
https://dl.dropboxusercontent.com/u/84552/tmp/issues/rt-30310.zip
The needed Enzo.jar is included in the zip file.
It looks like the area with the initial size is cached and won't be refreshed properly.