Help: Connecting from Classe SSP25 to CP-60?

I don't know why there is terrible hum coming from the main speaker whenever I use surround mode for movie on the CP-60. I connect the left and right output from the SSP25 to the surround input of the CP-60. Do I make a right connection? Has anybody use this combo before and has any problem? For two channel, the CP-60 works fine (no hum, noise or anything).
Do you think the surround mode was damaged? I aks this because I made a mistake to connect the input of SSP25 to surround input of CP-60 and turned on both units for about 10 min. Please help
Thank you very much.
I have all Classe products, and your connection mistake was, well, not good let's say. Possibly having two volume controls in series for the same amp is the problem.
The hum on the CP-60 was solved. I asked Classe and they told me to check the grounding on SSP-25 and CP-60. When I checked the power cord, I found out that I use PS Audio Lab II which has its own grounding. I disconnected the grounding of the PS Audio cord, and the hum went away. Moreover, Classe said that my mistake to connect input to input doesn't damage the unit.
Happy listining!