Bash autocompletion

[Michael Naumann <michael.n@strux.net>]

I find the TAB-completion feature of bash very handy and use
it everytime. Yet I have two issues with this feature.

a) I start a commandline like
scp gemini:/tm
here I press tab (gemini is a valid hostname in my network).
The line becomes:
scp gemini:gemini\:/tmp
and is thus pretty useless.
What can I do to prevent this?

b) If a file does not have the proposed extension the completion
will not work. Example:
I have a file called "Song of joy.mp2"
Now I start the commandline
xmms Song
Here I press tab, but due to the .mp2 (instead of .mp3) part
of the filename nothing gets expanded.
Can this clever autoindent feature be disabled temporarily?

Thanks, Michael