Is it surface mount? How many plane layers? Is the ground plane pretty contiguous or is it broken up a lot for routing use?
On what evidence do you conclude that?
clock.
What frequencies are giving you trouble? What is the clock frequency?
Where? Is the circuit in an enclosure? What is that made of? How are the signals entering or leaving the enclosure treated? Is your board connected to the enclosure near the openings that signals enter or leave?
I would expect the address and data lines to be about as spread out as the RAM clock.
That might help with high order harmonics. Have you tried increasing the resistor value? What kind of termination do you have on the clock and other high speed signals?
With a spectrum analyzer you should be able to tell whether it is the constant frequency clock or other, less constant transitions whose spectra are around the clock but more spread out. The address and data lines could easily produce the kind of problem you have described.
Do you have a means of evaluating incremental changes in your circuit's radiation at the frequencies causing the problem in your own lab? Or must you rely on test results from an EMC testing house?
You are welcome.