Gearing cables matey 
Doh !
The cables are a bit crap in my experiance. I use S2 exige gear change cables on my car and I have broke about three of them. I thought it was just me, but there have been quite a few failures apparently. Lotus now do an uprated “motorsport” cable.
I guess its pretty obvious when you break one, I wish I could pinpoint the prob as easily. May be worth getting a set of the motorsport ones as a precaution anyway.
I didn’tbreak the cable completly, just the inner plastic bit on the lever end, it basically made the lever go sloppy.