You can just add photos to the thread, with out photobucket. The system will try to make them a smaller file, if you all you have is the super megapixel file. just only do 2 to 3 of them at a time. the system is designed for 5 to 6 of them, but that can be too much, if you trying to do large files.
Tobie
PS-- what I meant if you didn't know, click on Advance, (under this screen) and then you will see the paperclip in the toolbar. (on the computer version (win7/8) phone versions, I dont know what options you have. What I tend to do, is I will view the image, and hit the print screen (alt+Prnt Scrn), then open up MS Paint, then paste it. and save it, (what ever default is, its fine) Then I don't have to worry about max pixel size, or the conversion time taking too long for complete converstion, pushing into a timeout for the ttl. good luck