Temper rebuilds.

Well Temper seems to help look at which files are getting rebuilt and has cut my rebuild time in half (still a long way to go). Looking at the activity log I have gone from 197 seconds and 34 entries in the activity log down to 108 seconds and 22 entries in the log - each rebuild was for an edit of the previous post.
I took out the rebuild of my style sheets, mt.js and the monthly by author and monthly by category archives as the first two are basically static, I only have one author on this blog - me, and the monthly by category is not really important as I don't have that many entries per category.
What I still don't understand is why I have 7 entry listings and 5 category archives for the previous post as it was only posted under 1 category (although it did have a couple of keywords in it - I can't remember how many though). This entry has no keywords and only one category.