Is this with the disk version of the game?
This is a known issue when playing the disk version in Vista or Win 7/8/10, which can be prevented by playing the game in Win 9x compatibility mode. Unfortunately, this only helps with a new game or a save before this started; once the inventory becames corrupt, switching to a compatibility mode will not fix or limit the problem.
Right click on the div.exe file in the install folder, or a shortcut for the game, and select properties, then switch to the Compatibility tab and select a Win 95/98/ME compatibility mode there (and maybe check off to run as administrator and disable display scaling on high DPI settings).
Inventory graphic placement bug
