Okay, I removed 1.9.9p1 from the store and submitted, it should go live soon.
The version in the store should now be 1.9.9f1 and should work in 6000.3.5f1 and higher.
If you previously installed 1.9.9p1 (the patch for 6000.3.0) and then updated to 6000.3.5f1, please re-download the package and install Playmaker again. It should say 1.9.9f1 in the About box.
This is the first time I've removed a version from the Asset Store so let me know if you run into any issues.