Hardly a day goes by without the suggested solution to a user's problem being to "Rename/recreate the preferences folder". This is not just for v5 but I have also seen it suggested for problems with v6.
I have no technical knowledge but as a regular users of Captivate (v5.5 currently), I cannt help wondering why Adobe have not got to the root of whatever is causing the problem/s that seem to only to be resolved by the "customer" (yes we are...) having to lift up the bonnet (hood) and tinker around in the engine.
Noel