Temporary fix (?) until someone pokes the actual SVN/files.wowace code...
Open up SpecialEvents-Loot-1.0.lua (in folder of same name minus the .lua part), scroll down to line 81 (if you don't have line numbers, look for "-- Parse coin strings (Really?)"). Replace the next three lines with:
local cg = '(%d+) '..GOLD_AMOUNT
local cs = '(%d+) '..SILVER_AMOUNT
local cc = '(%d+) '..COPPER_AMOUNT
I haven't actually tested looting anything (homework, doncha' know), but this quiets the error and matches what I've seen mentioned in a few places as the new constant names for WoW.