Im finally going to ask this in hopes that there's a simple solution that Im not figuring out on my own bcause my photoshop knowledge can be a bit limited in some areas.

Ever since I've started posing to the gallery its been like a crapshoot to get the sizing right to post. Sometimes I do and sometimes I dont. I've literally spent hours trying to get some to post and some pieces never do. 

I use Photoshop CS2 for postwork now, though I had the same problems when I used to use Elements 7. The Gallery specifications say max 4000x4000 and 512 kb. I've saved it to these specifications exactly, and I've also resized significantly smaller over and over. I've done every variation I can think of trying. Sometimes it wrks and sometimes it doesnt. Is there  a magic way to get this right? What does everyone else do? I've wasted so much time on this last one, I'd really like to post it but I'm about to pull my hair out.

Thanks!