This problem exists for many users in multiple templates. Searching the forums finds similar issues in Teline II Teline III Portfolio Travel and Purity either attributed to K2 integration or lack of and subsequently the SIGpro extension. There should be a separate forum for plugin/extensions like K2 so issues and any related solutions can be found in one place.
And if you found a solution please post it for the rest of us.
UPDATE
If using SIGPro you may want to try the newest version released this afternoon. V2.52
I had problems with K2 and T3 template overrides not working well together and the new version seems to have it fixed.