error starting ion3

Hi all,

I'm currently tring to run Ion3 on a freshly installed Gentoo Linux distro.
The installation seems to have been successful, but, when I type "ion3" in
an xterm, I get an error:
"Unable to redirect root window event for screen 0.
Refusing to start due to encountered errors."
The fact is that I'm new to both Ion and Gentoo (and very enthusiastic for
both), and that's not making things easy for me.

I tried to learn something from the X log, but it remains unchanged. I tried
to find out an Ion log, but did not succeed...

Can anyone told me how to solve this issue? Thanks.

Best regards,

BrokenClock