I have recently had a site that crashed with similar errors after importing new numbers and I ended up rebooting the CCS (Central Campaign Server) to get the site up and running again.
So I suggest to stop all campaigns and to restart your CCS.
Then
before re-starting any campaigns run the dialer tools on the CCS (Start - programs - Interactive Intelligence - Dialer tools) and see if there are any errors under the error recovery. Try to resolve these and then restart dialing.
Let us know how you get on.