Editing Cases should not affect their active Tests

Hi,

I've got a problem. Example:

I have got a Testcase and this testcase is in an active Testrun marked as passed. Now I edit the Case and the Test is edited too. This should not happen!

Two possibilities:
1. If a Tests is allready tested, than it should not be allowed to be changed afterwards, or
2. all active Tests, that belong to a newly edit test should be automativly marked as "restest"

A Test should never be changed, when it is already tested!

Thx, Jan

forgot the important part: How can I deal with this behaviour?