The Startup Suite is known to be a touch unreliable... I would instead suggest you use the ACADDOC.lsp
The ACADDOC.lsp is loaded with every drawing, if it doesn't exist in your support path, you can create it.
Type
(findfile "ACADDOC.lsp")
To check if one exists - and if so, where it resides.
To load a LISP routine using the ACADDOC.lsp, type something like:
(load "C:\\mylisp.lsp" "Load Failed")
Or you can exclude the whole filepath if the LISP file resides in the support path.
Hope this helps,
Lee