I use multiple frames for static objects and set the speed to 0 for scenery and other types of static objects. Is there any problem in using additional "in between" frames that are nothing but 1x1 empty pixels?
The reason I'm asking (in case you're wondering) is that I'm setting the frame of a specific sprite to a specific integer in an array, but some of the numbers are skipped and have no value (ie if you have 0-10, and it skips 11; 11 should be an empty sprite otherwise anything AFTER 11 will be the wrong image)
Hopefully I'm making sense?