Something is amiss... Posting an image shouldn't be this hard.
I assume you have a small (150 dpi) jpg image somewhere -
You enter some text, then
... You click the Insert Image at Cursor button above -
... You Browse to that image name -
... You name it - Description
... You click on Upload image -
And maybe add a blank line or two, some more text, then post ?
It should work. give me some clues....