Hello,
I have exactly the same problem. All .xlam and also .xla appear as Data-links altough I only have button(form control) linked to macros in the add ins.
The problem is that this happens only in some files but not in all of them. The only solution then is to break the link, which also deletes links in the form control buttons and I have to again link all th ebuttons with appropriate macros form the add-in.
If I then save the file and reopen it the data-links are gone and buttons are linked to the macros in the add-in.
But this relinking all of the form control buttons to the macros for every file is just too much so it would be nice if this problem would be resolved.
I'm doing all of this in Office/Excel 2010.
I hope someone has a solution to this.
best regards,
Borut.