Microsoft camera raw codec pack interferes with Lightroom?

Does Microsoft's Camera Codec break lightroom?

On Wednesday 26 July 2011 Microsoft added “raw” image support to Windows 7 in the form of the Microsoft Camera Codec Pack. This 8MB download will enable Windows users to decode vendor-specific “raw” files (a.k.a. digital negatives) directly from Windows Explorer, or from any application using Windows Imaging Codecs (WIC).

I wrote in a previous post why it is a good idea to “shoot in raw”. Problem is just that the raw files are large and clunky, and require special software to decode. For this reason some photographers (including Ken Rockwell) decide to shoot JPG, despite all the disadvantages of their approach. So this is great news because Microsoft just made it easier to live with raw files. Good job, Microsoft!

But… I downloaded and installed this codec, and immediately noticed something curious. It seems like the Microsoft Codec Pack interferes with the decoding of my Nikon’s D7000’s raw files in Adobe Lightroom 3.4.1. In Lightroom’s Library module the images are displayed as preview images but then remain at low resolution, even when zooming in. Only after switching to Lightroom’s Develop module are the files properly decoded at full resolution. I have only observed this for my specific camera (Nikon D7000) using my version of Lightroom (3.4.1 64-bit) running on my home PC (Windows7 64-bit SP1). But, tellingly, Lightroom resumed working normally as soon as I uninstalled the codec pack.

Not sure if this is a coincidence on my specific machine or a real wide-spread bug. Please comment on this post if you can confirm or debunk this issue.