Just feeling my way cautiously around Mountain Lion and all seems fine except for my Finder window sidebar which is strangely missing the usual icons for the items. The item text is OK.

I may well have somehow tweaked them in Lion (made them colourful perhaps?) but with what I cannot recall. There's no app that I can see on my iMac that would do this.

Is this a feature of ML and, if it isn't, does anyone know how to get them back? I have seen many references in the past to trashing the finder preference file as a troubleshooting method but have never had reason to do so. So ! was going to do this until I noticed there was also a finder plist "lock file" pref. Which do I trash?