This kind of falls under css so i didn't know if i should put it here or in the css forum but anyway.

I making this website, I'm doing all the coding using html and css but for some reason in my firefox browser the images when i use the code position absolute change depending on if i have tabs open. and depending on how many toolbars i have.

Is this normal to happen or does it usually not and if so anyone have any idea whats wrong.