i am running qgis 2.8.1 (OSGeo4W 64bit-version) on mac (10.10.3) and win (7)
... and was just recently confronted with different behavior of both versions when trying to open (ESRIs) file.gdb.
the following img shows the FeatureClass listing in ArcCatalog (see the two polygon FCs at the end)
this img shows the "add vector layer / directory / ESRI FileGDB" result on mac:
and tho following one the corresponding result on Win7
on win7 one table and the point featureclass are displayed properly
Why are the polygon feature classes missing?