Photoshop: Preference to set default Document Size unit type in Image Size dialog in CS6

Getting sick of constantly changing the unit type from inches to centimetres in the Image Size dialog window. Every time I open Image Size dialog, it's reverted back to inches (if my rulers are set to pixels).



P.S. Also getting sick of photoshop.com and adobe.com not saving the cookie/session — I have to log in every time after I close a browser window or even a tab (happens in all browsers).

If you guys require proper web coders, just let me know — I'll recommend a couple dozen for you.