What computer system, what internet system?
I use a IBM type pc, windows 7 and Firefox.
How I do photos is to right click on the image, select "copy image location". Then using the "insert image" icon above the area you type your message (looks like a yellow square with sum & mountain) I paste the copied location in the window that the icon opens up. Click OK and the magic should take care of itself.
Your image must be already posted somewhere on the internet first -----as I understand things.
This works for borrowing images also, here is the VAF logo for instance.

__________________
Mike Starkey
VAF 909
Rv-10, N210LM.
Flying as of 12/4/2010
Phase 1 done, 2/4/2011

Sold after 240+ wonderful hours of flight.
"Flying the airplane is more important than radioing your plight to a person on the ground incapable of understanding or doing anything about it."