I feel your pain. Seems like there's no end to the $$ one can spend on all this digital hardware, software, training, add-ons, etc.
Disclaimer: I don't own Elements or the HPPE tools, but I'm generally aware of how some of this stuff works... or at least how it's supposed to work.
It's my understanding that after Elements 1.0 and 2.0 Adobe has changed the underlying architecture of this program with each new version. As a result I'm not surprised by your report that the HPPE 2.0 tools aren't upward compatible to 3.0.
I just found the following verbiage (
http://hiddenelements.com/elements_5.html) confirming the need for version specific HPPE tools. Although written for 5.0 it conceptually applies to 4.0 and 3.0 as well:
"What is new in Elements 5: As with the previous editions of Elements, Adobe chose to change the implementation of add-ons, along with making some improvements to the program. This means those who purchased and previous version of Hidden Power will need to upgrade to the Hidden Power 5 package to access the tools."
I guess it's kind of like auto manufacturers when they change models each year: Last years' engine parts don't necessarily fit/work in this years' engines. Seems like they should, but in many cases they don't.
To Richard's credit he crafted these add-on tools that Adobe left out in order to make Elements an even more capable program. To make the tools work with new versions he had no choice but to comply with Adobe initiated changes and requirements over which he had no control.
So don't blame the author. Blame Adobe for changing the architecuture each time and/or for leaving out the functional goodies whose gaps Richard's tools fill.
Looking down the road if you decide to upgrade to Elements 4.0 or 5.0, be prepared for the same thing. What can I say?
On a cheerier note, Seaside, OR is one of my favorite cities to visit. (I used to live in Portland.) It's simply a wonderful town in one of the nicest areas on the planet -- winter or summer.