ok, thanks universalgeni. I will give K2 a try. Fortunately it happens to be a simple layout without unnecessary doodads, much like the Sapphire I currently use.
Just to see what happens, I tried previewing another template at random - Rounded - and it also shows posts full-length when listed by category, so apparently some do and some don't.
I didn't include the url because I thought readers would be able to reach my blog by clicking on my username...this is the first time I've used the forums.