#4 becomes unstable if device is unplugged

[David Costanzo]

gnopa (ver 0.1 pre 5) gets put into a bad state if the
device is unplugged while gnopa is running, even if you
plug the device back in.

If you try to copy an MP3 to the device after the
device has been unplugged, gnopa prints out many error
messages then asserts in GTK.

I have pasted the last screen-full of output below:

Seeking Error Before Read: : Input/output error
cpa-mp3: Reading FAT for card 1
Seeking Error Before Read: : Input/output error
Seeking Error Before Read: : Input/output error
Seeking Error Before Read: : Input/output error
Seeking Error Before Read: : Input/output error
Seeking Error Before Read: : Input/output error
Seeking Error Before Read: : Input/output error
Seeking Error Before Read: : Input/output error
Seeking Error Before Read: : Input/output error
Seeking Error Before Read: : Input/output error
Seeking Error Before Read: : Input/output error
Seeking Error Before Read: : Input/output error
Seeking Error Before Read: : Input/output error
Seeking Error Before Read: : Input/output error
Seeking Error Before Read: : Input/output error
Seeking Error Before Read: : Input/output error
Seeking Error Before Read: : Input/output error
cpa-mp3: Found 1 free chunks on card.
cpa-mp3: Chunk 0: address = 33 size = 7808
cpa-mp3: Found 7808 total free blocks

Gtk-CRITICAL **: file gtkprogress.c: line 518
(gtk_progress_set_percentage): assertion `percentage >=
0 && percentage <= 1.0' failed.