Error while implementing Visual Inheritance

hi,
After clicking OK button on the inheritance picker screen folowing all the normal procedures in Visual Inheritance of a form i am getting the following error

"Designer could not be shown for this file because none of the classes within it can be designed.The designer inspected the following classes inside the file:

Form2:The base class test.Form1 could not be loaded.Ensure that the assembly has been referenced or built if it is part of project."

Pls give me a soln for this problem.

TIA
srini

Did you build the project containing Form1, before you picked it as base class for Form2?