It must not have been a few easy days for the people of the Apple Mac team, as both Lion and Snow Leopard have presented various problems due to the latest update.
The problem with Snow Leopard is that PowerPC apps stopped working, something that for many was a problem because there are apps that are not compiled for Intel. Luckily Apple has reviewed the update and these problems have already been fixed.
If you had problems with the PowerPC apps you should download the latest update from this link.
Source | TUAW