I'm building a single switched AC/DC Forward Converter and have reached to the point where I have steady o/p voltages and currents. 

However, I am not able to remove noise that goes back into the AC i/p line. A multi-meter(DMM) placed across the Line and Neutral at the power line input jumps around wildly once the current starts flowing in the MOSFET. The o/p voltages and currents remain steady, however.
I tried reading the AC with an analog meter, but not much difference. As long as the load current is small, it shows correct AC voltage. But as the load current increases, the meter starts showing much higher voltage (roughly 400VAC)across the input.

I have tried various Y capacitors between i/p phase to Earth, Neutral to Earth, from the MOSFET source to Earth, but to no avail.

I have tried one commercial EMI filter also, but nope.
I have tried with a common mode filter that I rigged up, but either my design is wrong, or I haven't got the concept right, because it did not make any difference. 
Some pointers/URLs for a design procedure to correctly design EMI/RFI filters will be appreciated.

My configuration is a standard single switch Forward converter with 230VAC Power Line Input, a reset winding (Treset=Tprimary), and a P6KE diode as protection from Drain to +ve bus after rectifier and capacitor. The controller is a Micro. Switching frequency is 50KHz.

The output voltage and currents readings are very stable, but not the i/p readings.

Your suggestions,recommendations and advice sought. 
Thanks in advance