[nreel]

I'm speculating:

I think that, because your Radio Shack Distribution Amp is NOT powered independently, your Computer does NOT recognize it.

I use a Radio Shack S-Video-->RCA Adapter Cable and an RF Modulator depending on need.

Sometimes I use an RCA "Y" connection when I need to go to TWO TV's with RCA Inputs.

Sometimes I use the RCA-->RF Modulator-->COAX OUT to run TWO TV's with COAX Inputs.

With the COAX scenario, because the RF Modulator IS Independently Powered, my Computer recognizes a second connection even if I DO NOT have the TV's in the circuit.

So, this is the basis for my conclusion concerning your Computer VIDEO Card NOT recognizing a second connection...NO POWER on your Radio Shack splitter when Booting.

If you really want to amplify the signal using what you have, I would buy an RF Modulator and S-Video-->RCA cable.

Computer S-Video OUT-->RCA RF Mod Video IN-->RCA RF Mod Video OUT-->Radio Shack Distribution Amp Video IN-->Radio Shack Distribution Amp Video OUTS-->RCA Video IN of TV's.

Hope this helps,
Norm