Not sure if this is even still in active development. Anyhow:
You have a pretty serious bug in the extension handler for the additional context menu entries. When creating GDI object handles they are not freed properly, which will lead to a process making use of the explorer context menu to accumulate more and more of them, reach the system limit and ultimately corrupt the user interface of even unrelated programs.
You can use Technet Process Explorer to monitor GDI usage of programs.
