Comment Not news (Score 5, Informative) 275
The F117 that was lost in the Balkans NATO mission in 1999 was shot down by an S-125 modified to use longer wavelenths than the RAM paint on the aircraft would absorb. The issue has been known since then and it's very likely that the F22 and F35 low observability design characteristics have taken this into account as much as physics and material science will allow.