We are using the shortcut profile switch to specify a profile on the network on startup of ACA (I've found this problem with C3D too). The profile doesn't have a whole heckuva lot in it, just a few support paths, some plot style paths, and printer paths.
If I don't specify the main customization file (the OOTB aca.cuix), it will open with the OOTB acad.cuix.
If I specify the "MENUFILE" key, which would look like this:
"MenuFile"="%USERPROFILE%\\appdata\\roaming\\autodesk\\aca 2012\\enu\\support\\aca"
On booting ACA with the profile, I get an error that it couldn't find the path (obviously it's not reading the %USERPROFILE% syntax). I want it to boot using the OOTB aca.cuix on each user's local machine--so it needs the syntax.
If I hard coat the path, it'll open--but I didn't want the cuix on a network share.