This is the one I got. the M4, 8mm. http://www.ebay.co.uk/itm/M2-M2-5-M3-M4-A2-STAINLESS-PHILLIPS-COUNTERSUNK-MACHINE-SCREWS-POSI-CSK-BOLTS-/251395775686?var=&hash=item3a885b1cc6
Happened to me. I then got the M8 which I mentioned earlier but it happened again. Those M4 8mm are brilliant.
http://www.ebay.co.uk/itm/M2-M2-5-M3-M4-A2-STAINLESS-PHILLIPS-COUNTERSUNK-MACHINE-SCREWS-POSI-CSK-BOLTS-/251395775686?var=&hash=item3a885b1cc6