How to close a GIOChannel?

[Tomek Grzejszczyk <tgrzejsz elka pw edu pl>]

Hi,
I've a device which I open with g_io_channel_new_file and then I add it 
to the main loop with g_io_add_watch. Then I have a callback function 
connected to GUI in which I call:
g_io_channel_shutdown()

and when I leave this callback I receive another from... io channel I've 
just shuted down. The only way I can tell that I shouldn't read from 
device any more is... G_IO_FLAG_IS_SEEKABLE flag is now off (but 
G_IO_FLAG_IS_READABLE is still on, but on the other hand reading from 
the channel causes segmentation fault). Condition the callback gets 
called for is... G_IO_IN (not any of G_IO_ERR, G_IO_HUP, G_IO_NVAL as I 
might have expected).

Is this the way this is supposed to work?
Shouldn't a call to g_io_channel_shutdown prevent any further callbacks 
from a channel?

Greetings,
Tomek