Thanks for the replies.
Well, after an hour of messing about I gave up on trying to have my mods in My Documents and put them in the Addons folder in the main A2 program directory instead. I also had to remove the spaces I had in the "sjb sas v1.02" folder name I had originally - as either my launcher, Win7, or A2 didn't like them.
All working fine now. Great models btw :)