I have spent some more time listening to the noise, and would describe it as more of a scratching sound rather than a hum. It seems to be associated with the mirror up (video, live view, or m-up), and independent of whether SR is on or off.
Can someone try holding the pentaprism against their ear while running video and let me know their verdict please?
Cheers Rob

I have just noticed that my K-5 hums when in Live View and Video modes. It is faint, but distinct: I have to have my ear near the camera to hear it.
The hum seems to contribute to background noise when recording videos.
Do other people's cameras do the same?
Cheer Rob

Has anyone got a link to a reasonable sub £10 microphone please...

Hi
Has anyone bought a non-Pentax battery for their K-5?
Any recommendations for a good quality one?
Cheers Rob

I have just received a new Pentax K-5 and 18-135 WR from SRS. The camera was boxed, but the lens was just in bubble wrap?
Have other people received a box with their 18-135s?
Cheers Rob

There is indeed a small ball on the Pentax-A just round from the locking recess: this is flush at all apertures and then pops out on the "A" setting.

My teleconverter does not have a "protruding ball". Neither the lens nor the teleconverter have electrical contacts.

Thanks for all the input!

The converter does not have any electrical contacts, however neither does the Pentax-A 50mm.

I am assuming that the Pentax-A tells the camera that it is in Auto aperture by moving the aperture indicating lever.

Cheers Rob

I have a Vivitar 2x macro focusing teleconverter that I used to use very successfully on my Pentax MX.

I have been trying this converter with my K10D and a Pentax-A 50mm lens, but cannot get the camera to recognise the auto aperture position on the lens. With the lens on is own the camera recognises the auto position.

I am suspicious that the aperture indicating lever within the teleconverter may not manufactured to move far enough to indicate to the camera that it is in the auto position.

Has anyone got any experience of this teleconverter, or any ideas please?

Cheers Rob

Thanks to the "Run as administrator" tip I am running Remote Assistant successfully on my Windows 7 laptop.

One thing I did notice, which may or may not be helpful, or general was: if I inserted an SD card into the SD slot on the computer and used the "ready boost" facility to improve computer performance then Remote Assistant would no longer find and operate the camera. When I remove the ready boost functionality the camera re-appeared.

I think you may be able to use the built in flash as just a controller-so although it fires it is not used for illumination during the exposure?