If I understand the documentation for the STREAM and STREAMINIT routines correctly, the first (default) stream initialized has number 0. Which is, I think, the stream you initialize, right after which you switch to another stream, with a random seed. At least that's how I read the documentation. Unfortunately my SAS version is not quite up do date, so I cannot test it.
If I am right, you should get different results every time you run your datastep, and not just different results between DS2 and datastep. But perhaps the first stream was numbered 1 in 9.4m3, enabling you to get the same results in two runs. Or perhaps the STREAM routine was just a dummy in that version.
It's finally time to hack! Remember to visit the SAS Hacker's Hub regularly for news and updates.
Learn the difference between classical and Bayesian statistical approaches and see a few PROC examples to perform Bayesian analysis in this video.
Find more tutorials on the SAS Users YouTube channel.
Ready to level-up your skills? Choose your own adventure.