Let me get a clear view on how your PHP app works.
These effects you are talking about, these are applied to the image you upload right? Once the editing of the image is complete you overwrite the old image,
Is this what happens?.
you could try creating a random variable in your redirect to prevent cache.
for example
Code:
heading("imagePage.php?randnumber=".rand());
__________________________________________________ ________
I am DJ Kat...that's my name. Its a D and a J and a Kat with a K.