Crash when spellchecking certain characters

I'm experiencing a crash when right-clicking on certain characters while editing an e-book. I'm wondering if it's just me.

Steps to replicate:

Click the insert character menu. Choose mathematical symbols--> Mathematical alphanumeric symbols, choose the non-bold lower case k (it's the fourth available 'k'). In the editor screen it will be flagged as a misspelling. Right click it. At this point my calibre crashes, no error message.