Last upgrade 2.8.2

I started a new blog a month ago on the 2.8 platform. This was a fresh install. Last week I upgraded to 2.8.2 and all worked fine except for the speed the pages load. The site is now awfully slow. I checked with the hosting company and we went through different scenarios and decided that the slowness might be a wp issue.

My server has curl enabled. I have also gzipped all pages compressing them by 70% to 80%. The pages are very light, I had compressed all photos and thumbnails. Using the wp-cache plugin made no difference in the performance of the server and the hosting company said the load in mysql was *very* low so pages should be served up a lot faster.

I have checked one other site running the same theme and pages are served very fast. That other site is still on wp 2.8, not 2.8.2 like mine. Hosting company ruled out a dedicated vs shared hosting as they said mysql+pages on my site are light enough to have to respond quickly.

I would like to know if others are having the same problem and what else can I do to improve performance. Right now, pages take anywhere from 2 to 5 seconds to load. Horrible.