I'm not sure that Standard Edition was ever available off TechNet--I had to open a TAR and request a media kit when we went production on our site.
Unfortunately if you install the patchset that upgrades 8.1.6 standard to 8.1.7, you end up with EE. There is a closed bug in the Oracle bug database about it, their solution was to "not use the EE features to remain in compliance with the license". And I also think the patchsets that go from one release of 8.1.7 to another also reset the installation to "EE mode".
Definitely we need to stick to SE for OpenACS requirements. EE is insanely priced.
