Update iPhoto 11

I have an older iMac that is on its last legs, and I am trying to get my photos off of it and onto another drive. However, when trying to use iPhoto to see what is on the computer, I get some error messages that tell me that the version of iPhoto 9.2.3 is the current version, but one of the libraries I have shows in iPhoto Library Manager that it is version 9.5.1 so it won't open because the version of iPhoto is older. How can it be telling me then that 9.2.3 is the current version, unless 9.5.1 was created on some other machine with a newer version of OSX? The iMac is running 10.6.8. Is there a way to update iPhoto to be able to open the library that says it is version 9.5.1?