WowAce

What steps will reproduce the problem?

1. Do the Norushen encounter in SoO
2. Have someone reach 100 corruption then enter the Test realm and purify it

What is the expected output? What do you see instead?
Corruption should reset to 0
It's staying at 100 instead (until they gain some again).

What version of the product are you using?
1.68

Do you have an error log of what happened?
No Lua errors.

Please provide any additional information below.
At a guess UNIT_POWER (filtered for ALTERNATE_POWER) doesn't fire for units that are in the opposite phase than you are, so - for example - at 50%< that we have tanks soaking residue so dps can stay at full power it shows dps that purified themselves right before 50% as having 100.
This is a bit disorienting for RL :P

I haven't tried to switch scan mode from "single" (the default) to "full" to see if that makes any difference (it probably will)