The one I found was when Sirius shouts "KREACHER!" in Order of the Phoenix, but Kreacher doesn't show up.
In HBP, Dumbledore clearly states that everything (including Kreacher, along with the house and everything inside) was Sirius', as he was the only male in the Black family. This means that others like Bellatrix and Narcissa were not qualified to order Kreacher around, at least over Sirius. So they couldn't have made Kreacher disobey a direct order (summons) from Sirius.
Remember that when Harry screams Kreacher's name in HBP or DH, Kreacher appears suddenly, as he is not allowed to ignore the summons, and he has to submit immediately. Also, Kreacher "had to" Apparate out of the Cave, without even thinking about being able to(!), just because his master (Regulus) asked him to!
I have already countered the argument of others (like Bella) not allowing Kreacher to answer the summons. To counter the argument that "maybe Kreacher didn't answer on purpose, and then he had to punish himself for it, just like Dobby did", I have to refer you to the fact that when Harry tells Kreacher to shut up in HBP, he gags. Later, when Harry tells him that he is not allowed to communicate with Malfoy, Kreacher doesn't (despite the fact that he would rather break his own arm, than to betray the pure blood, lovely Draco!) as Kreacher is not allowed to disobey a direct order.
Dobby never disobeyed a direct order. He was just badmouthing his masters and he was allowed to do so, followed by punishing himself. The Malfoys wouldn't dream of their house elf spying on them for Harry, so they never asked him to never visit him.
To sum up, Kreacher not answering to Sirius' summons contradicts the rules and laws that Dumbledore states in the beginning of the sixth book.