disabling a modchip on the psone?

[zuker]

I just installed a 4wire modchip into a psone. I installed a known working copy of driver. It worked just fine. Then I started trying other games and all of a sudden a screen would come up saying to install the playstation boot disc. I have read in the past that there is a way to enable and disable the mod chip just by hitting the reset button in a certin sequence. Could I have inadvertantly disabled the chip some how? I could not even get the original games to work. So, I then opened up the psone and removed the chip from the socket. Pluged the psone back in and the original games worked fine. So, I then reinstalled the modchip back into the socket and powered it up. I tryied originals and backups. They all worked just fine. What gives? Anyone have any Ideas of what happened? This chip is from modchip.com if that makes a difference.
thanks
zuker