I'm still using my PCR-M50 with X3 Studio. I haven't tried ACT with it, but it's working fine.
Make sure you have correct USB drivers if you are using the USB output. The MIDI output doesn't need drivers.
My Soundclick Page SONAR Professional, X3eStudio,W7 64bit, AMD Athlon IIx4 2.8Ghz, 4GB RAM, 64bit, AKAI EIE Pro, Nektar Impact LX61,Alesis DM6,Alesis ControlPad,Yamaha MG10/2,Alesis M1Mk2 monitors,Samson Servo300,assorted guitars,Lava Lamp
Shimozu-Kushiari or Bob