This is something that I've seen a few times this week, but it seems to go away by itself after a while. Clicking on an Interesting tag takes me to the Featured list for that tag sometimes, when usually it just filters all questions by that tag.
I can currently recreate it thus :
1) While on http://stackoverflow.com , I click on one of my Interesting tags (eg sql-server). At this point I am not on the Featured list, nor have I been for at least an hour.
2) The link says https://stackoverflow.com/questions/tagged/sql-server
3) It takes me to https://stackoverflow.com/questions/tagged/sql-server as expected, but takes me to the Featured page for it rather than the Active one.
4) This persists until while in one of those tags I click one of the other buttons at the top.
Additional oddities :
1) While on main page, I select Week
2) I click on a tag, expecting to filter the Week section based on it.
3) Instead, I'm presented with the Featured list for that tag again.
I can also click on Hot on the main page, select a tag and get the featured list again.
I've been trying to work out a pattern to the odd behaviour, but nothing yet. At first I thought it was an issue with the selected tag not having an equivalent to the screen you were previously on (Active/Week), and therefore selecting Featured by default. But it's not that.
Has anyone else experienced this, or can recreate it every time? Or am I missing something obvious?
FWIW, I'm using Opera 10.01 and I've seen this on 3 different PCs and XP32/XP x64/Win7 Pro 64-bit.
EDIT : Ok, after nosing around the Questions page for a change rather than just the main page, the behaviour when clicking on the Interesting Tags is consistent - it will remain on the tab you selected within the Questions page. However, when starting from the main address http://stackoverflow.com the behaviour is somewhat confusing. If I'm on the address https://stackoverflow.com/?tab=featured and I click on an Interesting Tag, I expect it to take me to the Featured tab for that tag. Instead, it takes me to the Questions for that tag, and the tab shown is whatever I last used on the Questions page (which in my latest test case was Newest). So, I now understand what it's doing...but it's sometimes acting counter-intuitively.