Something's broken

Forgive my ignorance gents but I'm not as familiar with the workings or parts of my handgun as I should be but I will try to expain: there are two flat 'round pieces' with a small hole in each one right down from the front rails on the frame right next to the rectangular slots....one of those round 'pieces just looks like it was sheared off!!! The right side ( if you're right handed) is the one that broke off....what piece is this and I take it I'll have to send it in??? Nothing has ever went wrong with my M40-A1 since the day I brought it home so I'm pretty sad over this... I was taking it apart to clean after the range yesterday so.... thanks for all your help mod06

 

Thanks for the reply syntax....actually I did contact SAI and talked to Jeff...I expained it to him and he said it is the multi function sub assembly 'lobe'....he said it is where the spring went when the model had the manual safety. He said Austria still uses the manual safety so it remains part of the piece....clear as mud right! anyway, great guy...amazing customer service....said i should have it back within a week...i'm overnighting it today and he said should have it fixed and sent back to me by Friday....he said he has seen it once before....Thanks mod06