I don't know how much you can help me because its under the NDA, but I recently updated to the OS 4 beta 3 xcode version. My project worked fine under 3.2 but under 4.0 parts are a not quite right I assume because it is still being developed.
Every other installation of the beta sdk I could go into the project settings and select the iPhone 3.2 sdk and then change the target iPhone OS in the top left of Xcode but not this one. If I select 3.2 it still loads on 4.0 it seems I only have the 4.0 simulator and the iPad 3.2 simulator.
Any ideas how to get the 3.2 Simulator back?