Like Mark I'll post this here. See the bloaty stars. Using Mike and John's advice I've minimised them but bloaty they still are. On balance I think my focus was off. I refocused for the M42 I've already posted, and I put it down to the lens cooling down. I now think that it wasn't properly in focus in the first instance.
(http://gallery.orpington-astronomy.org.uk/albums/userpics/10006/m45_dsc.jpg)
Pleased with the (minimal) nebulosity captured, but needs longer subs. A guiding here I come.
BTW Mike, I confirmed on the Skysensor last night I had the autoguide port switched off. B*gg*r...
Yep looks like a combination of PE and out of focus. There is a slight dimple in the stars that looks like PE to me.
As for your guiding port..... DOH !!! :o
Definitely looks like focus is soft.... John