Thanks for your bug report. This is due to how font support was originally added to the scripting language. The Windows API supports positive (cell height) and negative (character height) font sizes. The scripting commands use cell height, whereas the font dialog uses character height. To use character height in scripting comands, you need to specify a negative value. In your example, a value of -11 will match 11 in the font dialog. This is currently described in the /font command entry in the help file.
