I am experiencing this exact frustrating issue. I had Streamline 3.1 working yesterday. Did a complete reinstall of Oblivion overnight because I was having issues with another mod. Installed OBSE, Streamline 3.1, and the patch from the 7zip directly to OB/Data, started a brand new game....and no Streamline. Checked the install, reinstalled three times thinking I must have screwed something up. I can't figure it out. The only thing I kept when I reinstalled OB was my OB.ini. I guess I'll try the clean save, but a new game should have been clean, right?