LC: Party rebuy when all in: Is it wrong to use this to build a stack?

[Fergdog]

Lately I've been playing the 15K Guaranteed on Party, and I've been able to end up with a stack of 25k to 35k after the rebuy period is over, by pushing any decent holding, or any pair and rebuying while all in. It's not exactly a maniac strategy, since I'm only doing it with good cards, and usually when it's only short stacks in the hand. I do feel a bit guilty though, should I? Is this a bug in their software? I don't play on any other sites, does this work on sites other than Party? It seems that If I don't use this to my advantage, them I would be seriously short after the break. Thoughts?