You mean when you are viewing your projects (similar to events in iPhoto) in "Projects" view and renaming them? Immediately after changing the name the thumbnail grid will scoll up to the first project - I am seeing the same in Aperture 3.4.5, when viewing the projects sorted manually.
But I noticed that this does only happen, when I press the "Return" key after changing the name. When I simply edit the name of the project and instead of confirming this with "return" select the neighboring project the grid will not scroll. Try it please - do not press "Return" after editing the name, but select the next project- I'd like to know, if that is the same for all.
I do not know, why this has been implemented this way, but the same can happen in the browser after editing images. There seems to be some kind of "Reset" after renaming projects. You may want to send feedback to Apple to report this bug: Apple - Aperture - Feedback
Any way to fix this?
No fix, sorry.
Don't press "Return" or hit the background. I use the "Info" panel in "Projects" view to step the projects and to edit the project names and other Metadata.
You open this panel by pressing the "Info" button in the lower right corner of the thumbnail. Then you can use the arrow keys to step the projects.