When resizing a (Vim-) window don't use the CLEAR flag as it causes the status line to be redrawn (which causes problems for plugins like Command-T). The reason CLEAR was used in the first place was because resizing a window would cause display corruption due to wide letters like "w" spilling over into the neigboring display cell. To circumvent this problem we now always clear neigboring blank cells whenever a cell is cleared (just like other GUIs deal with faked bold glyphs spilling over into neighboring display cells).
The proxy icon is only disabled when the current buffer is modified (previously this happened when any buffer was modified). This also has the consequence that the dot in the red "close button" only appears when the current buffer is modified.