Adding a photo to my profile

I'm having some trouble for some unknown reason uploading a photo to my profile. Everytime I try to upload one, the little field next to where it gives you the option says "cannot upload this file" and nothing else, no reason. Are there certain dimentions that it must be, does anyone know? I mean, I assume it needs to be pretty small, but I found a small photo and still nothing. Can anyone tell me?

If you have a picture and you can't upload it, resize it. (Smaller)
It FINALLY worked for me that way.

xTheEcstasyOfSuicidex

I'm having the sammmmeee problem! Lol
I know what you're going through it's a pain in the butt!

it took me ages to do it but i did!!!
but it was quite a while ago so mabey what A.T said is happening now
you need to reduce the amount of pixels and make sure the format is correct
hope it helps
(unless it is broken)
xxx

What format? how many pixels? This is the information I need.

go onto photoshop and resize to like 10, or keep on goin down till it works. that's wot i did here and it worked