Entire other libraries showing up in Inbox of unrelated libraries?

[ziffel]

I'm not sure if this should be in bug reports, or if it is user error, but lately i've had this issue.

I have about 8 or 10 distinct libraries (new age, comedy, main, classical, etc)

Lately I'll be in one library, say, Main, and its inbox will have one of the other entire libraries in it (as if detected). I check the library settings and it is set to only detect the desired library.

What might cause this, or where should I look?

thanks.

edit: v. 3.1.6590