memory card issue

i have a xolo q800
with a sandisk16 gb ultra

two days ago i upgraded my phone to 4.2.1(official)

and since the
whenever i connect the phone via usb the memory card doesnt show up
and in place , "removable disk" is written

but the phone internal memory drive shows up fine

also, in the file manager it correctly shows the free and the used space, my songs, pics etc

please help!