Hi all,
Disclaimer: IANAL
I agree that using two different licenses leads to confusion and should be avoided.
But IIRC you can put the same piece of code under different licenses, because a license is a contract between the author and the consumer/reader/audience. When you license your code to Alice under license A, and to Bob under license B, you just have placed two contracts.
But I may be horribly wrong on this.
Cheers, Stephan