I don't know this is an Ubuntu issue because I have an Atheros chipset and
have never experienced like what you describe and if it was common you can
be assured that you would not have trouble finding others with the same
problem. The fact that you can't suggests that it is likely something else.

The fact that something works in another environment may or may not be
useful information. Things work or not for various reasons. There are
different drivers, different network managers, etc. There may even be
something in your home that interferes with the connection and it could be
coincidental based on time of day and not OS. It could be a driver issue
that has nothing to do with Ubuntu (they don't make drivers). It could be a
bad copy of Ubuntu. There is no way to know based on what you have written.
We should not ignore the fact that it could be a bug in Lucid, but that is
not necessarily the case.

To troubleshoot, I would look at trying any of these things:

Remove wicd and try network manager (that could pin it down to a network
manager issue). Try a different desktop environment such as KDE by
installing kubuntu-desktop in Synaptic (that could pin it down to driver as
they would be the same). You will need to login into KDE at login using the
session manager. Neither of these involves much effort and is reversible.
You could install madwifi divers (in the repos). You could add backports to
Lucid which would give you access to newer applications and drivers. You
could look at blacklisting or changing your settings files.

https://help.ubuntu.com/community/UbuntuBackports

If nothing works, then try the latest version 10.10 Maverick which uses a
newer kernel. Finally you could try a variant of Ubuntu such as Mint rather
than go outside the family by using Mandriva which is a fine distribution,
but hardly the same.