On the FEG hi power I just got the hammer follows the slide forward to the 1/2 cock position about 80% of the time when shooting and always when releasing the slide manually.  

The sear/hammer surfaces look unmodified and the sear spring seems like it should be strong enough to hold.  

I noticed in an exploded diagram that there should be a spring in the slide to hold the sear lever away from the sear - based on the drawing on numrich's site, I have the "type I" sear lever.  

My sear lever freely flops back and forth - should the "type I" sear levers have a spring or is it only the "type II"?  
If the sear lever is down, it seems like the angled end hitting the sear could be enough to trip the sear - has anybody had this problem?

It's slow in here!  I took the hammer out and the sear notch had obviously been filed on.  So I filed some more to give the sear notch a reasonable profile.  Stoned all the surfaces up and put it together.  Removed the magazine disconnect also.  

The trigger is smooth as glass with no creep now.  The pull is even decent.  And the hammer doesn't follow the slide ever when releasing the slide.  Will shoot it at work tomorrow to verify the hammer stays cocked when firing as well.  

I traded an inexpensive gun I didn't even want for this thing and it was well worth it.  

Thinking about striping the bluing and parkerizing it.  

Edit: shot 30 rounds and it functioned perfectly.  

So someone tried to modify the sear notch and buggered it huh?

Good for you for finding the problem and fixing it.

Hope it shoots good for you