Hillcrest and 250hz Custom Firmware ? HELP

[3dvison]

Hello everyone,
I had installed the custom 250hz firmware a long time ago on my FSM-6 module (also known as the FSRK-USB-2).
The problem is, I can no longer down grade to the old firmware anymore ? It is no longer listed on the firmware upgrader program as an option and I have no idea where to download the old firmware.
The real problem is that Vireo with Half-Life 2 is unusable with the 250hz firmware,the view jumps all over the place, but it was fine with the old firmware.
Any Ideas how to fix this or find that old firmware ?