Can anybody help. I have update manager giving me a warning symbol - a red exclamation mark and it won't go away.

This is the message I get:

Code:
Fetched 14.4 MB in 34s (413 kB/s)                                              
W: A error occurred during the signature verification. The repository is not updated and the previous index files will be used. GPG error: http://dl.google.com stable Release: The following signatures were invalid: BADSIG A040830F7FAC5991 Google, Inc. Linux Package Signing Key <linux-packages-keymaster@google.com>

W: A error occurred during the signature verification. The repository is not updated and the previous index files will be used. GPG error: http://debian.wgdd.de lucid InRelease: The following signatures were invalid: KEYEXPIRED 1319053487 KEYEXPIRED 1319053487 KEYEXPIRED 1319053487 KEYEXPIRED 1319053487 KEYEXPIRED 1319053487 KEYEXPIRED 1319053487 KEYEXPIRED 1319053487

W: A error occurred during the signature verification. The repository is not updated and the previous index files will be used. GPG error: http://debian.wgdd.de maverick InRelease: The following signatures were invalid: KEYEXPIRED 1319053487 KEYEXPIRED 1319053487 KEYEXPIRED 1319053487 KEYEXPIRED 1319053487 KEYEXPIRED 1319053487 KEYEXPIRED 1319053487 KEYEXPIRED 1319053487

W: Failed to fetch http://debian.wgdd.de/ubuntu/dists/lucid/InRelease  

W: Failed to fetch http://debian.wgdd.de/ubuntu/dists/maverick/InRelease  

W: Failed to fetch http://dl.google.com/linux/chrome/deb/dists/stable/Release  

W: Some index files failed to download. They have been ignored, or old ones used instead.
E: Could not get lock /var/lib/dpkg/lock - open (11: Resource temporarily unavailable)
E: Unable to lock the administration directory (/var/lib/dpkg/), is another process using it?
I tried the following:
- Changing software sources location to best location and main server but no luck
- sudo apt-get update but no luck

Any ideas?