If the CRM 4.0 Database store the date field as DateTime in SQL 2008, and the DateTime object accept dates before 1900, when the CRMDateTime object doesnt accept that ?
I can't dig up what CRMDateTime.MinValue equals but assuming it's 1900 as you sugsest what difference does it make if the data base can hold earlier dates? The only way to the data base is through the CRMDateTime object.
PS- what do you mean by DateTime object? The .NET object? It's not compatible with the CRMDateTime object.
I think the answer to your question is, you cannot. I also have a hard time believing you've got contacts for your enterprise whose birthday is before the 20th century. Something tells me that if the object can't handle the date neither can the date control -- i.e. the application is forcing you to store such information as a string.