Gallery thumbnail spacing problem after 3.1 upgrade

I seem to have fixed this problem by modifying style.css. I am still concerned this may become an issue at some point. I also thought posting this may help someone if they have the same problem.

I’ve made lots of modifications to my theme and WordPress defaults so this may have been part of the problem, I don’t know. Before the upgrade and after the upgrade, I didn’t disable any plug-ins, I just went straight to the css after I discovered the problem.

The problem that I encountered after the upgrade was that all of my gallery thumbnails were now all clumped together. I have 4 thumbnails per row.

The default in my style.css file under
/* Gallery */
was:
.gallery-columns-4 { width: 25%; }

I changed this to:
.gallery-columns-4 { width: 100%; }

Now all seems to be back to normal.

I’m curious if anyone else had this problem or if there is something else I should have done instead.