I don't know if this has been already reported. When you have two albums with the same name and different artist the album browser messes when I double click one of of them. The list of songs shows the album I want but it starts playing both albums from both artists. I'm using last git version.

I think the problem is in fact that the second FilterPane ignores the selected filter in the First FilterPane for actions such as play (double-click).
So if you select an artist in the first FilterPane, and an album in the second, the listed songs will be those matching the selected artist in the selected album. But if you double click on the album, all the songs from that album will be played.
I will probably change that, though I'm not completely sure what the best behavior is. If the first filter is "best songs", and you double click on an album, do you want it to play only the "best songs" from this album, or all the album ? The same thing happen when you drag-and-drop the filter btw.

To make gmusicbrowser recognize the 2 albums as separate, you have to fill the album_artist field of at least one of the 2 albums (only possible in v1.1.x)
On that subject, I will soon add an option to enable a mode where albums with different artists and no album_artist are recognized as separate albums (so you have to fill album_artist if they are in fact from the same album).