So you should use the correct version of cgminer, as sidehack said.  If you aren't submitting at the minimum requirement with slush's pool, it will go offline.  I think that's 10gh/s - not verified though - so you should be good with one stick running at 100 MHz.

 I believe that means that you are submitting shares that are below the minimum threshold.  Does it eventually show "offline"?

A couple of items to try:
        1) reinstall the zadig driver: start zadig -> options -> list all devices -> select the 2Pac -> reinstall
        2) restart your machine.
        3) remove the extension cable.
        4) run in verbose/debug and read through the logs for hints.
        5) try on a different machine (ideally linux based) to confirm the usb miner is healthy.