This is the major thing that turned me off about Kohana. I loved the original concept - "PHP5 fork of CodeIgniter" - and we actually have it backing our two largest web apps. But I would never recommend Kohana again for a commercial project that is under active development.

Between minor versions there was major API breakage, that wasn't really documented - and was going on in parallel with 3.0 development (think Rails 2 -> 3 with no documentation). For a long time the "Unofficial Kohana 3 Wiki" was actually the only source of documentation for KO3 (even after release).

It seems like the PHP community keeps fragmenting into new PHP frameworks to replace old stodgy (cough PHP4) frameworks (good), with modern design practices (good), but then totally ignoring the community aspect of OS software, documentation, and maintenance.