Yves, I am not sure i have a problem now :D i think when i was using iTGB to do iphone, i was cropping them in mmf and exporting them, and putting them into a sprite sheet, perhaps the issue was there.
As i have just tried one of the animations and it worked perfectly. Will keep an eye on it, and see what happens :D But at least i can save some more memory.
Added "Too many transitions at one time" section
Replacing the fade transition :)
Added "Overuse of "text" counters/score and strings" section
That's a surprising one to me - why is drawing text such a performance hit?
This is a good guide, though - I've already started to take some of its suggestions on board, like the use of a scaled small white active instead of a full-screen one, and it'll be useful to give people something to guide them towards efficiency, which is something that you don't usually need to consider in MMF.
Because you're handling strings, which are in escence immutable and therefore expensive to modify.
It is also because first the strings needs to be drawn into a bitmap and then transferred to the iPhone graphics card to be cached inside a texture. This in itself goes really fast, but it can be slow for big texts if you do it all the time on many objects. For small texts it will not be much of a problem.
Couple of things, alot of people (including myself) use counters as a way of storing information... so should there be a tip for that? would hiding the counter save any memory? Most of the time its only to do basic calculation.
Crap tip, but certainly something i do :)
Tip - Consider going through your frames before release and remove any images that you no longer need. Many developers drop images outside the play area while they "design" the game, trying different combinations before completing the game. Its not unusual to find graphics that you decided not to use in your game, still in the frame. These take up precious memory.
Invisible counters are basically completely free to use memory and performance wise (almost). I'm only talking about stuff that is being drawn to the screen at the moment.