The homepage is quite good for having a look at what's going on across the site - not sure why it would be dumping you there from other pages, but it is fairly harmless.
Don't know if it is relevant but in my experience, if you look at a different page in a different window/tab (say the latest posts page for example) and then answer a query, the page that comes up is the one from the other window/tab. The site seems to hold the memory of the last page downloaded rather than the one you posted an answer to and gets itself confused.
Each page is created dynamically so your browser will cache the newest page; this does mean if you're working on various posts you may end up being dumped to the "newest" question.
As Gromit says, one of the oddities of the system I am afraid.