I'm having an issue with alignment in a toolbar, with DOCTYPE specified I get the following:

However, if I remove it, I get the toolbar as I expected:

Why is this, and what's the fix? I can leave DOCTYPE off for now but that's not a long term solution? What's curious is the toolbar below seems unaffected.

The layout is stacked like this:

Toolbar Panel (Affected)
Toolbar Panel (Unaffected)