weak repository key

[Floris]

After updating to apt version 1.2.7 I get a warning on apt-get update:
W:  
gpgv:/var/lib/apt/lists/partial/dl.google.com_linux_chrome_deb_dists_stable_Release.gpg:  
The repository is insufficiently signed by key  
4CCA1EAF950CEE4AB83976DCA040830F7FAC5991 (weak digest)

and the repository is ignored

Is there a way that apt re-trust the old SHA1 key, or do we have to report  
this to Google and all other repos?

Floris