Webmail problems

[#1]

There is a similar thread here http://community.plus.net/forum/index.php/topic,88972.0.html but I'm not using IMAP.
Sometimes I can't login but get the "Error, Unknown user or password incorrect, Go to the login page".
Other times I can login without trouble but accessing an email or replying to an email brings up the same error message even though the folder structure is still visible on the left hand side. This happened twice with a reply yet the reply was posted!.
I have screen captures if they are needed.
Using Firefox 3.6.9 on Sabayon Linux 5.4 KDE

[#2]

You are using IMAP if you are using webmail.

[#3]

Quote from: Midnight

You are using IMAP if you are using webmail.

Thank you for that. It had never occurred to me as I always use POP3 and Thunderbird, just going to webmail if I'm away from my machines.
Are you still getting problems?

[#4]

I wonder if there is a connection with another problem; If I send an email to my PN address it is bounced back. Here is a munged extract from the bounce message:

Subject:
Delivery Status Notification (Failure)
From:
Mail Delivery Subsystem <mailer-daemon@googlemail.com>
Date:
Sun, 03 Oct 2010 11:15:17 +0000
To:
xxxxxxxxxxxxxxxx@gmail.com
Delivery to the following recipient failed permanently:
     xxxxxxxxx@xxxxxxxx.plus.com
Technical details of permanent failure: 
Google tried to deliver your message, but it was rejected by the recipient
domain. We recommend contacting the other email provider for further information
about the cause of this error. The error that the other server returned was: 550
550 #5.1.0 Address rejected xxxxxxx@xxxxxxx.plus.com (state 14).
----- Original message -----
Received: by 10.227.129.149 with SMTP id o21mr6413972wbs.176.1286104517753;
        Sun, 03 Oct 2010 04:15:17 -0700 (PDT)
Return-Path: <xxxxx.xxxxx@gmail.com>
Received: from [192.168.1.74] ([81.174.196.136])
        by mx.google.com with ESMTPS id g9sm3019764wbh.19.2010.10.03.04.15.16
        (version=TLSv1/SSLv3 cipher=RC4-MD5);
        Sun, 03 Oct 2010 04:15:17 -0700 (PDT)
Message-ID: <4CA865C4.3020100@gmail.com>
Date: Sun, 03 Oct 2010 12:15:16 +0100
From: xxxxx xxxxx <xxxxx.xxxxx@gmail.com>
User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9.2.9) Gecko/20100926
Thunderbird/3.1.4
MIME-Version: 1.0
To: xxxxxxx@xxxxxxx.plus.com
Subject: 4th. test email
Content-Type: text/plain; charset=ISO-8859-15
Content-Transfer-Encoding: 7bit
tested

[#5]

Quote from: sabayon

Are you still getting problems?

Yep, on and off

[#6]

Update:
Still having occasional problems getting kicked off but the other problems are now sorted. I wasn't aware of the necessity of turning "catch all" on to receive all emails addressed to anyone@mynode.plus.com. I did raise a ticket and have been informed that the problem of getting kicked off or not always being able to logon are recognized as an open problem that they are working on.