Proper way to terminate a HPGCC C program after using hpg_set_mode_xxxx()?

[dkostan]

I am on a HP49G+ and am using this mode:

hpg_set_color(hpg_stdscreen, HPG_COLOR_BLACK);
hpg_set_mode_gray16(0);

Works great I can draw text, boxes, circles etc. However when ending the program it always locks up the calculator, usually a blank screen. I have tried all combination of the below calls and no luck. Does anyone know how to properly cleanup before exiting the program when using the graphics modes? Thank you in advance!

WAIT_CANCEL; // wait until ON pressed
hpg_cleanup();
hpg_init();
hpg_set_mode_mono(1);
hpg_clear();
hpg_set_mode_mono(1);
hpg_set_color(hpg_stdscreen,HPG_COLOR_BLACK);
return 0;