I use for a long time now a program called Colibri, which I use to start programs with. My typical hotkey is a combination of "Alt + ^(Circumflex)". But I noticed a problem which caused the dialog window to appear, but also wrote a "^" into the search field, causing the search not to function properly, as the program that was searched for does not contain this character.
I found out that if I exit Synergy the problem is gone. So I am quiet sure that Synergy is somehow hindering/repeating the hotkey.
I hope this problem to be solved in the next version. I was not quiet sure, if I should write a bug report, but if so please tell me and I will write one.