When I save the mind map as a PDF file, it freezes

I am using OS X 10.8.4
When I try to save the mind map as a PDF file, it freezes. After a restart of the application, I lost some modification before the freeze. It was stressful.
My guess is that I am using Japanese characters as the file name, I trie once to change the file name to Alphabets, it worked.
If the problem is what I guess, it will be a bug need to be fixed. I hope the develope team notice this and provide an update ASAP. Thank you in advance.
I love the application very much by the way. Without the mentioned problem, it could be perfect, please fix this.

いろは about SimpleMind Pro, v1.7.2