Official Interference?

[thefan]

Anyone see the Fed-Blake highlight? At about 1:50, Blake hits an amazing crosscourt winner but the umpire calls an "official interference". What happened during that point? And what is an official interference?

[psp2]

Didn't one of the ballboys drop a ball onto the court?

[Fedexeon]

No, the linesman called out but the umpire overruled it.

[Mick]

actually, the same linesman changed his call and the umpire declared it to be official interference. See below.

http://sports.yahoo.com/ten/photo?slug=6f76aa9e95334e7498ea8651e3e1a6cd.cincin nati_masters_tennis_ohab109&prov=ap