Ratchet and Clank: A Crack in Time is good, but it's not perfect. That is, of course, why Insomniac just released a patch for the title which fixes a bunch of stuff you may or not have known was broken.
The update (1.20) fixes up a nasty bug that would mess up player's saved games, so if you fall into that category, rejoice. Other fixes include bugs like not being able to damage certain bosses, trophy-related snags, and more. While playing the game for review, I didn't run into any such bugs, but there's little doubt they did exist... because they're fixed now.
Insomniac has the full list of fixes on its Web site. If you held off picking up and playing A Crack in Time, wait no longer -- it's not broken anymore!