Roy,
I've hesitated for a while now to put this in writing, but I think this is the time.
On the understanding that this is meant constructively and in friendship, then...
I've seen this "look" in your pictures ever since you got your 40D - even with shots taken with the prime. Your pre 40D gallery shots often show more feather detail and have a less "processed" look to them.
I think that maybe your 40D and lens aren't very well suited to each other and need calibration.
I believe you might be over sharpening and otherwise over processing (and having looked at this thread on three different computers now, only one of which - mine - has a calibrated monitor, I have to say I'm seeing heavy over sharpening and over processing) to make up for images that are coming off the camera too soft.
In other words, for me it's not about the amount of sharpening you're using per se as much as it is the possibility that you aren't getting as much fine detail and sharpness in your pictures in the first place, and are having to PP them heavily (to the point of losing "naturalness") to try and account for that.
Roy, can you do me a favour please?
Can you make an unprocessed copy of the blue tit jpeg available? Better still, the RAW file? I'd really like to have a go at processing it from scratch my way, and posting up the results.
I'm not saying that what I do is "better" - indeed I am not - but I definitely do things "differently", so it'd be revealing I think, to compare results with the blue tit you posted...