Those spoilsports at EA have released an update to the PC version of FIFA 13, which corrects a number of issues including online connectivity problems, "general stability during gameplay" - oh and that thing with the invisible ball. As Eurogamer point out, occasionally the ball would become invisible in the middle of a match, resulting in a sport that can only be referred to as 'Foot'. That's now been fixed, along with "rare cases of physics elasticity when two players collide". They must edit those bits out of Match of the Day.
If you're unsure whether to get FIFA or PES this year, don't let increased ball visibility sway your decision. You can find our reviews for FIFA 13 and Pro-Evo 2013 right here. Spoiler: we liked EA's effort quite a bit more, summarising it as "a still excellent football game that has been overburdened by features and is hungry for some real innovation."