Do you have an iPhone?
If so, go into your PB (PhotoBucket) app...
choose the picture you want to post, and let it expand to just that 1 pic with a bunch of buttons around it to choose.
Then look to your bottom right, and you will see a white circle with a black lowercase "i" in it. Click on that.
Then you will see all kinds of URL Link codes, etc... Choose the one at the bottom that has IMG beside it.
A Blue box should pop up that says, "Copied IMG Code."
Then exit out of PB, go back to your forum, and in this same box that I'm typing in now.....Double click and it should give you 3 options.....Select "Paste" and it should paste your image code into your Reply Box. Then just hit "Submit Reply" and it should post up a full-size picture.