I've had no such problems. I've been using LR4 since it became available on a 3 year old Intel Core2 Quad CPU Q8300 @ 2.5GHz, 8Gb RAM, Win 7 x64 Pro.

I was having general performance issues with my machine up to about 3 months ago when I reloaded it from scratch. Those problems have now gone away and everything works like new again. Now I make system images periodically to avoid that necessity in the future.

Perhaps it's time for a reload of your PC, or at least run something like CCleaner on it to tidy up a bit, do a defrag etc.

Interesting results I think.

Now I'd like to know how many of those who voted "Never Checked", have now checked, and whether or not they have had to make any adjustments.

I'm not certain that there is any functional difference between the Pentax Auto Bellows M and A variants, only the name. Both are operated by a double cable release, one to operate the shutter, the other to stop down the lens. There are certainly no electrical contacts in the A version.

EDIT: You just got in before me Brian.

I can't remember exactly which model or firmware version, but some users noticed an increase in AF performance after a firmware upgrade to their cameras where AF performance was not listed in the improvements.

It's not unheard of for manufacturers to slip in corrections to software/firmware without telling us what the correction is or what it does. Adobe Lightroom updates always have the catchall phrase in their software updates, something like " . . . includes other corrections and bug fixes not listed above" or words to that effect.

I always update to the latest firmware simply because we are not always told the whole truth. Whilst a list of changes usually accompanies an update, there are sometimes other changes in an update that are not listed.

If you are using the lens with the aperture ring on the 'A' setting, it should stop down OK.

If you are using the aperture ring to set an aperture and you are using a Pentax DSLR you'll need to change a menu setting to "Permit use of aperture ring". You'll find the setting in the custom menu somewhere. If this is not set, the lens will not stop down.

When detached from the camera, turning the aperture ring to any setting will not stop down the lens. It will only stop down when the aperture lever is moved to close the diaphragm to the chosen aperture.

All that said, if you can see that the blades are sticking, send it back for a refund,

I don't think so Brian. I think we'd all prefer our images to be blur free in-camera, unless we purposely wanted them blurred. Now, if it were added to camera firmware to de-blur images in-camera, that would really be something else. Software anti-shake, awesome.

Apparently the last image they showed in that clip was synthetically blurred, but the first two were real images.

Very impressive I think. I wonder if it'll make it into a future version of Lightroom.

Take a look at this.

I believe they are cumulative.