v15 bricscad acad toolpalette conversion issue

gday from oz, first time post. Using Bricscad V15 and having a problem converting my toolpalettes from acad. Imports acad xtp file ok but the symbols won't insert.
I'm trying to insert a symbol named 'A' and bricscad is looking for a drawing named 'A' containing block named 'A'. this won't work of course.
I've spent a little bit of time comparing working briscad btc files with acads atc files and there are some differences.
I'm not sure what is causing bricscad to do what its doing with an imported acad xtc file but changing over to an .atc file renamed .btc file bricscad behaves the same.
Anyone come across this and is their a cure. thanks