Under "setup" if you set your modules as X10 modules, they should work. Either from the screen buttons or the channel and volume buttons (volume controls lamp brightness).
Since your TM751 is a test bed, set it to A house code and using the Setup/X10 menu on the IR32, setup A1 as appliance module and stand next to TM751 when testing. If you don't hear the TM761 clicking, either you have not set it up correctly, or the IR32 is not transmitting the RF codes.