I'm using a 2560x1600 display, and every time I try to resize the images, they become crushed horizontally. Any chance that you could possibly resize the theme for 2560x1600 help.
I have looked at your situation and don't understand why the images end up crushed?
Doing the math of dividing the required size by the original size and multiplying by 100:
Width 2560 / 1900 = 1.34 x 100 = 134%
Height 1600 / 1200 = 1.33 x 100 = 133%
Therefore resizing your required graphics (as explained in the
Resizing Themes Guide) by 133% for both the X & Y results in correctly proportioned images. Have another go and see how you get on.