D3 Form inheritance and Win32 API errors

I've been trying to get an application to share a common menu structure
accross a number of forms. To do this, an abstract "baseform" is created
from which these other forms are inherited. I also have a MainForm that is
never shown but is the application's Main-form.

I use it to switch to whichever form is the currently active one.

None of the inherited forms are AutoCreate, they are all created when
required.

All works OK until I have about 6 or 7 of these inherited forms open in the
IDE- i then get one of several problems: a Win32 API error, or I can't look
at the project options at all or if I do see the project options i sometines
find that there are no packages defined. Lately i have also experienced low
resource memory probs - ALL IN THE IDE- not once the program runs.

Any ideas???