Interesting series of shots. To be honest, I'd have gone straight to the last one without really knowing why until now

What make is the lens?

If you didn't already know, it's a Praying Mantis. Those black spots in the eyes are similar to the pupils in our own eyes. The whole eye turns black at night.

If you are seeing grey blobs in the same place on various images, it's almost certainly dust on the sensor.

A rocket blower should get rid of all but the most sticky dust (probably pollen). When it becomes necessary, which is very rarely, I use an Arctic Butterfly brush from Visible Dust.

One or the other or both should sort it. If not, you might have to resort to a wet cleaning system. I wouldn't use a brush from a cheapo brush/blower if I were you. The Giottos Rocket blower is the best.

IIRC the K200D has a 10Mp sensor which I think is the same as the K10D. You may have to use the Pentax cleaning kit, or Eclipse 2 fluid and PecPads. The original Eclipse fluid is not suitable for the 10Mp sensor because it has an additional anti-dust coating.

It would help us to help you if we knew which camera you are using. As it has a mirror we can guess that it is an SLR. Which model?

What do these artefacts look like. If they are grey fuzzy blobs you have dust on your sensor. Follow the cleaning procedure in your manual.

If they are bright spots you have hot/stuck pixels. These are common and can easily be cloned out using post processing software (like Lightroom, SilkyPix, CaptureOne and others). Most software will remove them automatically during its noise reduction process.

In any event, you should not touch the mirror with anything. If you must remove the dust, use only an air blower, not canned air unless it is 100% guaranteed to be oil and/or propellent free.

If there is dust on the mirror, focussing screen, pentaprism/pentamirror, it will not affect your images anyway as the mirror is raised before the shutter is released and none of these is in the light path when the image is exposed.

Paul Daniels lived close to me when I was in UK. I regularly saw his plate MAG 1 C. Jimmy Tarbuck had/has the plate COM 1 C.

You're welcome. I hope you get to the bottom of it and get it sorted.

If file numbers are sequential, either:-

A) The bracketing function failed in some way.
B) You didn't keep the button pressed as long as you thought.
C) There is a problem with the shutter release button.

Try repeating the test with a cable release if you have one. That would help eliminate B and/or C.

It could be a dud card if files are missing (gaps in the file numbers). Did you format the card in-camera before using it?

Try another card and take a few tests. Reformat the possibly suspect card and try again.

Just bouncing ideas really.

Can you let us know the bracketing order that you have selected. There is a function in the custom menu to set/check it.