The requested URL's length exceeds the capacity limit for this server

Hey,

we have a similar problem.
When I try to search (Quicksearch and host search) for over 800 hosts to set a Downtime, i get same error.

Is it possible to increase this value or is there another way to set a downtime for 800 hosts or more?

EDIT:
With a view I can list the hosts, but as soon i activate the check boxes, I get the same error again.

Best regards