Image Stabilisation and why they therefore have to make twice as many lenses as are strictly necessary...

I can see why everyone else was so keen to get hold of that KM now!

I have a genuine adapter here and also one of the 3rd party copies. The designs seem pretty much identical, although the copy isn't quite as well machined as the genuine one. The copy was about £5 including postage from Hong Kong. £65 is utterly ridiculous!

I did hear a good one a while ago relating to the "Sending the new guy for a long stand"

The new guy managed to find a "long stand" in the parts catalogue, and ordered one having been told to obtain said part. It ended up costing his boss some staggering sum of money!

From the three you list, it's the one I'd pick. I love manual primes but I just think the prices for 50mm f1.2s are utterly ridiculous - the f1.4 isn't much slower and costs about a quarter as much!

The Pentax DSLRs don't support TTL flash AFAIK?

You can still use that over-powered flash as an off camera slave unit, you just need a £5 slave flash trigger from ebay. I keep meaning to have a go with mine using the camera flash to trigger the slave with an old AF200T attached to it. As doing it this way means you have no electrical connection between the camera and the high-voltage flash it's fine.

The AF200T is actually a pretty handy flash, has a fair bit of manual power control.

The problem I have always had with home-made frames is the inevitable ragged edges on the mitres. Any hints on how to avoid this? The only thing I've ever managed to make splinter-free cuts in wood with is a hacksaw (due to the very fine teeth)!

If you have a builder's merchant nearby they may be able to cut glass to order, which is well worth it compared to the hassle of trying to score and cut without ending up with a horrible mess.

I'm not completely ham-fisted, having built a fair number of models over the years and being pretty handy with anything mechanical. The materials used for picture frames, however, seem determined never to let me win!

I'm not terribly impressed with mine. However, it has a lot of scuffing on the front element which may have caused the softness I wasn't happy with. I know most people find them ok if you stop down a bit and I'll be keeping an eye out for a spares or repair lens with a good front element to rebuild mine to original condition.

The Pentax-M 28mm f3.5 is a cracker though - very sharp indeed. It seems to be regarded as better than the f2.8, certainly my experience is that I now leave this lens on the camera most of the time as it's sharp, compact, and a useful field of view.

I find mine goes much better with half an exhaust pipe...

First step with any electronic device - try taking the batteries out and leaving it for a few hours until any residual charge has dissipated, then reinsert known good batteries. If that doesn't cure it I think you're looking at talking to Pentax Service.

If the aperture is merely stuck then I'd use it to bargain the price down, but it wouldn't be a dealbreaker providing the lens hasn't been butchered. I've seen some horrors on ebay where people have mangled the stop-down tab but providing everything is present and undamaged (but jammed) it shouldn't be too hard to fix.

Assuming the Viv S1 is a K M mount all you normally need to do is take the lens mount off and drip some lighter fuel into the aperture mechanism, this is usually enough to free it.