Originally posted by funktionsfrei I wasn't aware of having stept right into a beehive when mentioning "Sigma" and "Pentax" in one posting.
First, congratulations on your new K-1!
Second, too bad that you are having an issue with your Sigma 70-200/2.8. The K-1 should never freeze under any circumstance, independently where the ultimate cause is. If that happens in conjunction with equipment that works fine with other Pentax cameras, it is just a sign of a lack of robustness. There are no two ways about it.
Third, it is not your fault that some people find the need to lash out against a third-party manufacturer. If Pentax had offered a lens with similar specifications and a similar value for money prospect, you would have bought it, right?
The notion that Sigma is taking "shortcuts" or does things "cheaply" is ridiculous. The vast majority of their products work just fine with original equipment but now and then orginal equipment manufacturers find the need to throw a spanner in the works and change the protocol slightly, even when no additional functionality is added. Just take the slightly altered hot-shoe of the Nikon D750 which makes a lot of useful third-party equipment useless or a lot harder to use and even creates incompatibility with some of Nikon's own equipment! This incident clearly did not expose third-party shortcuts, but very clearly was an attempt to persuade customers to stick to Nikon products.
Also, I wonder to what extent people who insinuate illegal behaviour on Sigma's part have checked when the respective K-mount patents expired. Who can actually prove that Sigma is doing something sleezy? And if it costs Pentax money (rather than helping to complete their own rather incomplete lens line-up), why aren't they suing? Nikon has sued Sigma for an alleged infringement on their stabilization technology. Why isn't Pentax suing Sigma, if the use of their very, very old technology is illegal?
I hope Sigma can sort the problem for you. Sigma has responded very well in the past to firmware incompatibilities and my experiences with Sigma service have all been extremely positive. The only problem I could foresee that your lens model does not exist in large enough numbers to justify the development of an updated firmware.
Let's all hope that the introduction of the K-1 will mark the beginning of more demand for K-mount lenses again. If production of K-mount lenses becomes financially viable for third-party manufacturers again, perhaps we can get more choice from Sigma again, and regain the support from Tamron, Zeiss, Voigtlaender, and Tokina.