Just noticed that the Jucer generates 2 lines for JucePlugin_IsSynth:
#define JucePlugin_PreferredChannelConfigurations {1, 1}, {2, 2}
#define JucePlugin_IsSynth 0
#define JucePlugin_WantsMidiInput 0
#define JucePlugin_ProducesMidiOutput 1
#define JucePlugin_IsSynth 0
#define JucePlugin_SilenceInProducesSilenceOut 0
This is also the case in the JuceDemoPlugin.
No big deal, but redundancy might cause problems 
Just thought I’d mention it.
Edit:
Oh yes, this is with the latest tip in git. Don’t know how to uniquely identify revisions in a nice way in git (if at all possible…), but the commit ID is this:
Commit:e663b1a04c09e8730465a145f15d9a39c48f0b00
I ran the Jucer on Windows 7.