You may get ILE if you have been living together for 4 years as an unmarried partner so it shouldn't matter if there is a combination of unmarried and married.
http://www.ukvisas.gov.uk/en/howtoap...vespartners#Q5
At the moment it is really worth getting ILE rather than the spouse visa if you can as it means you'd be under the existing rules rather than the new rules (probationary citizenship, etc) that will be introduced in July 2011.