The line: ICON "IDI_ICON", 1001, 48, 48, SS_ICON should be enclosed within a DIALOGEX statement - as it denotes an ICON control as apposed to the resource itself
Aaah, It might be the number of parameters you are providing
Try adding a width and height parameter (I have used 32 for width and height here, but you can use 0 because windows always use the real icon width and height)
ICON "IDI_ICON", 1001, 48, 48, 32,32, SS_ICON
Also If that compiles without error, but the icon doesn't show, then try (without the quotation marks) ICON IDI_ICON, 1001, 48, 48, 32,32, SS_ICON
Yep, that was it, the correct version is ICON IDI_ICON, 1001, 10, 10, 32, 32, SS_ICON and SS_ICON is optional, however, unlike MSDN documentation says, the width and height are not.