The best way to report a problem is by using the "Report a bug" feature, under the Help menu.
In the dialog that pops up, do the following:
We will get back to you as soon as possible.
Important notice: if you have purchased and activated PosterGenius, the system will automatically detect your identity and let us get back to you. In case you are using the free Trial Version of PosterGenius, you are totally anonymous to us. To make it possible that we get back to you in order to troubleshoot your issue, please include your email on your report as well.