[Zope] We get problems Zope is backed up!

Does anybody have a solution for our big problem? How do we backup in another way...? When our Zope-site is being backed up we have different probs... We have (kind of) have figured out that the problem is only (!) occuring when we change something on our site OR somebody adds something to our site, while it is being backed up... We are using Zope v2.2.4 running in Apache on a Linux-machine.... ( = Stoons = ) - Webmaster @ 3D festival (http://www.3dfestival.com)