1. Make sure you're logged out.
2. Open two HN pages.
3. Log in on one of them.
4. Click an up arrow on the other page (the one where you're not logged in).
5. The vote will get counted, but you'll be sent to a blank page.
I always figured it was a failure of the AJAX to check login status.
Ah, interesting observation. The difference is actually that the up arrows don't have an onclick attribute if you're not logged in, so you end up with the vote behaviour you normally get if you have JavaScript disabled.
1. Make sure you're logged out. 2. Open two HN pages. 3. Log in on one of them. 4. Click an up arrow on the other page (the one where you're not logged in). 5. The vote will get counted, but you'll be sent to a blank page.
I always figured it was a failure of the AJAX to check login status.