Jumbo Frets

Hi everyone , I have just finished building an acoustic dreadnought based loosely on the D28 model and even though it took forever I'm quite pleased with the results. At least I was until I started to play up and down the fretboard and noticed that each and every string is causing a scratching or scraping sound when I bend the string. I double checked my measurements ie. string heights , nut and saddle etc etc and everything seems to be exactly where it should be in that respect.

So, now I'm looking at the jumbo frets that I installed--probably not my best ever decision but they are installed now and I really do not want to go through doing a refret . I'm leaning towards putting the blame on the jumbo frets for the problem ,as even though I did level and re crown them the tops are still flat. It would appear that my crowning file did not put a nice enough crown on the tops as each fret is quite flat across the top.   I'm hoping that someone here who has more expertise than I do will be able to throw some light on whether this could be the problem ?
I dont want to go to the expense of buying a special diamond file unless I know for sure that its the frets. I have tried all the standard fixes that i could think of but it has not helped and I'm still getting the scraping noise every time I bend a string--its a very obvious noise and not string noise you sometimes get when sliding up to a note. 
Any help or advise would be much appreciated
Thanks 
Rusty