Sqeaky Brakes

[adamf92]

The brakes have been squeaking for a while now when pressure is applied to the brake pedal. The discs and pads are all fine, and infact were only recently replaced. In the past I have sprayed copper grease onto the shims and this seems to temporarily solve the problem for about a month, only to then discover the squeeking slowly returns.

Is there anything I can do to prevent this from happening? This is on my 2005 MK2

Thanks in advance