bilyth,
Actually, I did realize this applied to the WS12a - I have seen WS467's and LM465's with the new "features".
Congratulations, you've encountered one of the great foul ups of X10.
The switches themselves are not the problem. They actually have some very nice and useful features. The screw up was the fact that X10 did not assign them a new model number and program a new interface within AHP to use the new features.
X10 chose not to do this and, as a result, the existing WS12a interface in AHP doesn't play well with these newer units.
Fortunately, Charles Sullivan found a work around some time back.
Try re-identifying your units as LM14a (2-way) Lamp modules. These units use the extended code "direct dim" protocol to directly set the lamp level. This should get you around the unit remembering it's last dim level.
When using this in a macro, you may need to program a level of 99% rather than 100%. If I remember correctly, AHP will send a simple "ON" command for a macro bright level of 100%. The on command would cause you switch to return to the last dim level. By programming a 99% level (with the LM14a interface) AHP should send the extended code "direct dim 99%" command causing the switch to go directly to that level.
If this works (If these units are like the WS467's it should) you'll learn to love the speed and reliability of the direct dim commands. I have the same features on my Leviton switches (at 2x the price) and I love them.
I'm on the road at the moment and can't verify the above - give it a try and get back with us.
Boiler