pr cs6 xmp files missing upon project open

hi all,

i'm using pr cs6.05 on mac osx 10.8.5.

when opening a project file i've already worked on, premiere is asking me:

Where is file '00006.xmp'?

i'm using avchd footage in mts containers. so i navigate to the nested STREAMS folder where the 0006.xmp file lies. now, unfortunately all contained xmp files are listed but "greyed out", i.e. not available for selection.

i don't understand the sense in asking for the file but not allowing me to select.

also, i don't understand why premiere looses the connection to xmp files it previously used.

can anyone please explain how to proceed in this situation?

thanks
chris