Comment 2 for bug 729848

It seems that the problem involves the use of the useimg variable in the assert function. The assert function requires a boolean value but the useimg variable is clearly an integer which can at times be less than 0. The following change to the subgen-image.c file on line 900 (the error message states line 897 but it's line 900 in the version I'm using) will enable you to create the menus without any errors.

//assert(useimg);
assert((useimg > -1));

Unfortunately there are some serious issues with the buttons in the finalized menu even after making the change above. The menus are created without any errors but some of the buttons don't appear at all until you hover over them. Or the borders that surround some of the buttons may be missing or may be the wrong color.