I didn't see a bug report quite like this (there was a different freezing one). This is not a crash, as it generally comes back, but it is a bit annoying, especially when it is embedded into kontact, and freezes me out of my mail.

I am subscribed to 38 different feeds, and have 4545 posts archived. Is this excessive? Is this working for other people?

(To be clear, when I say switching feeds, I mean that after reading all the new posts for one feed, I'll click on the title of another feed then get an hourglass [or orbiting spheres as the case may be...])

Also the akregator website hasn't been updated since 2006. Is this project dead (or dying?)

It might help to clean out the archive of posts, it sounds like Akregator is performing some parsing in order to provide a list of items in a feed.

However, this would still be a bug, because Akregator should be capable of handling large amounts of feeds / archived posts without significant slowdown. This would point to the parsing algorithm being inefficient

38 feeds and 4500 archived posts is by no means excessive. I have considerable more feeds and posts and do not notice such a freeze. I do get a sort of akregator gui refresh (the article list and display window display only their borders) when going to another feed, but it doesn't take more than 5 sec. to resume normal behaviour. It happens at random, but no more than once or twice while browsing the entire feed list.