How to filter pulse like jumps in a signal? I have a noisy signal with jumps to high value and back to normal for limited time bins (40 for example) which I want to filter to have a smooth signal with no jumps. Here is the graph, the blue one. 



I tried moving average filter (n=20), the green one. Also tried window based (kaiser) LPF with cut-off freq=0.01 (I choose it manually) but still the filtered signal follows the jumps. 

Also I tried to flatten the signal by using the average of the past n values whenever there is a jump. But how could I find the start of a jump. I need a threshold. Also there is difficulty with determining the end of a jump. I need another threshold. 


Is there any way to filter the signal in a way that it doesn't follow
the jumps?  
Are those jumps and falls caused by low frequencies, since LPF don't eliminate them? So I should use high pass filter? I am confused.


EDIT: Another graph that shows what I want to eliminate (the gray regions).
I think that you will not be able to get acceptable results with linear filtering because the impulse noise covers the whole frequency range. You may want to look into nonlinear filtering techniques. As a first (and simple) approach try median filtering: http://en.wikipedia.org/wiki/Median_filter

I think if you optimize the window size of the median filter you should get better results than with purely linear filtering.