unicode (Polytonic Greek) problem


I am currently using a trial version of Scrivener (Windows). I intend to buy the software, if only one problem were not bugging me. I am conducting research in Ancient Greek literature, so obviously I often want to take notes that contain Greek words or sentences. In order to do that in e.g. Word, I use a tool called Multikey, which enables me to write Greek unicode. This does not seem to work with Scrivener, which is weird: since it is unicode, it had been working in every single program I had ever used.

When I try to type Greek in Scrivener, the first letter appears… and keeps appearing, whatever I am typing. So, instead of ‘ψυχή’, what appears on screen is: ‘ψψψψ’, and whatever I type during that run of Scrivener, is the same letter. Interestingly, when I close Scrivener, start it up again, and try another word, e.g. ‘λόγος’, the repeated letter changes and all I get is 'λλλλλ᾿.

I would very much like to use Scrivener for organizing my notes, so I hope anyone has a suggestion for solving this problem. Thanks in advance!