I'm using Ubuntu 11.10 in a VirtualBox VM on a MacBook Pro with the default Unity UI. Positioning the mouse cursor over the 1-pixel wide border to resize a window is driving me absolutely nuts. Lots of people have asked the same question but all the advice I've found for fixing this doesn't seem to work:
In System Settings > Appearance, there are four themes (Ambiance, Radiance, HighContrast, HighContrastInverse), all of which have exactly the same size resize border.
Installing other packages (e.g. human-theme) has no effect on the theme selection.
My laptop doesn't have a middle mouse button, and even if it did, I don't want to use two hands to press Alt + middle button just to resize a window. In an attempt to change the resize key binding, I installed compizconfig-settings-manager and ran ccsm. Any changes I make to the Initiate Window Resize binding in the Resize window plugin have no effect. In fact ccsm seems to do nothing at all.
I discovered that the previous issue is because I'm using Unity 2D instead of Unity (3D), even though I'm picking the non-2D desktop when I log in. Unity 2D has no equivalent of ccsm as far as I can see. And when I configure VirtualBox so that the 3D Unity starts up, I get completely screwed up window behavior (missing all borders, don't accept mouse clicks, etc.). Sigh.
I hate to use the M word, but on the Mac all windows also have a 1-pixel visual border, but the invisible resize border is actually usable (it's at least 8 pixels wide on the edges, plus a nice big rectangle in the lower-right corner). I don't think implementing usable resize behavior should be up to each individual theme; this is a lower-level functionality issue and should work right in every theme. What's the right package to file a bug against for this?