Photobucket is not an option for me anymore. I can still see Photobucket uploaded pics because I use the "Photobucket Hotlink Fix" add on my Google Chrome browser.
I host my pictures on Flickr. However, free accounts are now limited: only 1000 uploads are allowed
Anyway, this is what I do:
1) upload the pic on Flickr
2) after upload, open the pic on Flickr
3) click on the "Share Photo" arrow icon on Flickr
4) Copy the "BBCode" URL, always choosing a size no bigger than 1024px.
5) Paste the URL on the W900 "new post" board
6) Erase all the URL bits and bots, except the [img][/img]
7) Post it!