Noise in Lumix cameras

My main line of camera equipment is Cannon EOS but I had a Lumix DMC FZ28 to carry around. I noticed that this camera has a lot of noise. I gave this away and purchased the newer model FZ100 which seems to have even more noise than FZ28. I found twao identical photos the left hnd one made by FX28 (left) at ISO 100 and the right hand one made by EOS 450D @ ISO 800. Both hand-held. The noise in the Panasonic made photo is terribly higher, although the resolution of the two cameras are too much different (10Mp in Panasonic and 12 Mp in Canon). In my current FX100 the noise level is even higher, although resolution is 14.1 Mp. Is there a reason for this difference in quality? Anyone have made similar observations?

 

I have the same problem.