Simple circuit, stupid problem

I'm trying to build a two transistor LED flasher, as shown at
http://www.reprise.com/host/circuits/transistor_flasher.asp. It should
be perfectly simple, but I must be making some mistake that I'm just
not seeing yet.

When I build this circuit, both LEDs light continuously rather than
flashing. I've tried varying the values of the resistors and caps that
should control the timing, but it doesn't make a difference. I can
actually pluck the capacitors right out of the circuit and both LEDs
are still lit. I've built this thing a dozen times now from several
different people's instructions, and I get the same result every time.

The transistors I have on hand are a little mixed... I've tried
2N3904s, 3906s, and 4424, any of which ought to work as they're all
NPN.

Does anyone have any suggestions as to what stupid mistake I'm making
here? I am starting to get sick of looking at this thing. Thanks in
advance..!

.

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