help, what to do about workitem attributes when the workitem type changes.

we are running 3.0.1.1.

we have a custom Defect workitem (and attributes on all other workitems) that make the workitems non symmetrical.

and we have run into a couple problems..

1. I create a workitem of type Defect, and for some reason, I need to convert this to Task. (we will handle the
   work in the new development, under a Story).
   the 30 fields in Defect that aren't in Task are now on the Custom tab of the Task workitem.. as seen from
   Eclipse

   except.. that the custom tab does not appear on the web UI at all.

2. we need to add a temporary variable to Epic, that will be deprecated when our requirements Mgmt tool comes online. we decided to put this on the custom tab so that we wouldn't have to change any of the training material to document the new field on the overview tab. (when u need to train 5000 people its no small task to keep things up to date)..
   but the custom tab doesn't show in the Web ui.. oops.. thats the tool the team uses, cause they are in plan view, and plan view no longer works completely in eclipse ui.

I cannot hide a tab.

help..