Synaptic problems with Ubuntu synaptic package manager

Is this part of your sources.list?

$ sudo apt-get install gstreamer0.10-plugins-base gstreamer0.10-plugins-good gstreamer0.10-plugins-ugly \
    gstreamer0.10-plugins-bad gstreamer0.10-plugins-ugly-multiverse \
    gstreamer0.10-plugins-bad-multiverse gstreamer0.10-ffmpeg

If it is, please remove it.

Debianmigrant thanks! I won't bother you with "wow, such fast response..." and other compliments, am sure you've heard it all before.
To our point, I have done as requested, saved the editor file, restarted synaptic, and the same error persists. I have removed all the repositories and started afresh, and once again the same error persists upon hitting reload.
Thanks again....

You also need to remove the following:

 sudo apt-get update
X

from the sources.list file. It should only contain the following:

# Treviño's Beryl-GIT Ubuntu Repository
# GPG key: 81836EBF
deb-src http://gb.archive.ubuntu.com/ubuntu/ dapper main restricted
## Major bug fix updates produced after the final release of the
## distribution.
deb http://archive.ubuntu.com/ubuntu/ dapper-updates main restricted universe multiverse
deb-src http://gb.archive.ubuntu.com/ubuntu/ dapper-updates main restricted
## Uncomment the following two lines to add software from the 'universe'
## repository.
## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu
## team, and may not be under a free licence. Please satisfy yourself as to
## your rights to use the software. Also, please note that software in
## universe WILL NOT receive any review or updates from the Ubuntu security
## team.
deb http://archive.ubuntu.com/ubuntu/ dapper main restricted universe multiverse
deb-src http://gb.archive.ubuntu.com/ubuntu/ dapper universe
# Uncomment the following two lines to add software from the 'backports'
## repository.
## N.B. software from this repository may not have been tested as
## extensively as that contained in the main release, although it includes
## newer versions of some applications which may provide useful features.
## Also, please note that software in backports WILL NOT receive any review
## or updates from the Ubuntu security team.
deb http://archive.ubuntu.com/ubuntu/ dapper-backports main restricted universe multiverse
deb-src http://gb.archive.ubuntu.com/ubuntu/ dapper-backports main restricted universe multiverse
deb http://security.us.ubuntu.com/ubuntu dapper-security main restricted
deb-src http://security.ubuntu.com/ubuntu dapper-security main restricted
deb http://security.ubuntu.com/ubuntu dapper-security universe
deb-src http://security.ubuntu.com/ubuntu dapper-security universe

Yes, I agree.
This is not needed and would cause errors:

# Treviño's Beryl-GIT Ubuntu Repository

# GPG key: 81836EBF
sudo apt-get update

X