The latest update of Java from Apple introduced some major problems for Java based products like failing to draw or respond to user input. More exactly we are talking about the update to Java SE 1.6.0_51. The problem also applies to RationalPlan users.
As a quick fix Apple released the patch Java for OS X 2013-004 that should fix the above mentioned problems. We recommend users that encounter such problems to install this update by following this link where they will also find more details.