Problem When Maximising Chrome

Had an issue appear recently. When I maximised my Chrome browser, it was slightly wider than the screen. This meant that the wrench icon slightly moved off the screen, but more importantly, the right side vertical scroll bar was positioned off the screen. I could resize it manually, but this was just slightly inconvenient.

This is how it looked:

I am running the developer version so it may well be a bug introduced in this version (12.0.742.12 dev-m):

I discovered that removing the theme caused the browser to behave as expected: