Four icons per row in Vista

I'm not sure if this really is a bug or if it is Vista we should blame. I recently migrated from XP to Vista and was planning on using my old config, which was two rows of icons with four icons in each row.

Using version 4.2 64-bit in Vista 64 Ultimate, I can only achieve this as long as the toolbar is unlocked;



With the toolbar locked;



Is there a solution to this problem?

I just tried the latest beta and the problem went away.