now i have discovered that the problem was in fact, after all, the pop-up window blocking in Norton Personal Firewall 2003. (at least on my computer. there may be be other programs that cause the problem, because i think i've had the same problem on computers that weren't running norton firewall.)
BUT...it doesn't matter if blocking is on when you click the LINK. it only matters if it's on when you LOGIN to gmail. that's the secret, and the source of my confusion. i had been turning it off after having already logged in. the fact is, after you've logged in, you can turn blocking back on and the link will still work, as long as it was off WHEN YOU LOGGED IN.
also, you can leave ad blocking on, it's only popup window blocking that causes the problem. but you do have to click "ad blocking" and then click "configure" to be able to turn off just pop-up blocking without turning off ad blocking. they're both lumped under "ad blocking" in the main menu.
by the way, if you have a network-capable version of the HP LaserJet 1320, you won't be able to access its browser-based settings page with norton ad blocking on. (it's the opposite of gmail: you can leave norton popup blocker on, just not ad blocker. or heck, just turn them both off!) i suspect this applies to other HP networked printers (they call them "JetDirect" i believe.) and you need javascript enabled i think.