3.61 will not work; Playstation 3?

My question is, did it completely download and then have the error when trying to install, or was it during the download itself? If it was during the download for the update, then my guess is due to the overwhelming number of people accessing the PSN servers due to the release of the Welcome Back package, it's having trouble downloading the update. Other than that, I can't say what the problem could be as I've never had an issue downloading any updates. So I would say just keep trying.