Symbol weirdness

Im using CS4 and Ive been following some tuts but I cant understand whats happening.
These are the steps-
1.Draw object -tick
2.Convert to movieclip -tick
3.Double click and go inside movieclip and make a motion tween.- This is where something weird happens. When I try to create the tween Flash says “you must convert to symbol before you can make a motion tween”.
I thought I already did this in step 2.
Where am I going wrong? The tut I followed didnt appear to have to make a symbol twice so how come I have to?