In Yggdra Forest NF, the Wintery Dirge is not at the 11k,29k location. They are located at 10K,56k a small camp of 4-5 of them. Also the drop rate on the Frozen Teardrops are like 1 in 15 to 20.
Group of four of us killed them for a bit at the Ghostly Albion site NW of Grallahron in Yggdra Forest. Most would drop a tear a kill. Rarely would they drop nothing (see comment above about being level 40), occassionally they would drop two.
Got 13.2 million per tear when I turned them in. Nice easy XP with a small group. Add to that the Ghastly Albs drop kill task items as well (Vial of Ghastly Vapors) and Soulsong (same camp) drops a Hauberk (think you have to be at least 40 to get, not sure. 39 Zerker did not get rest did as we were all 41-42. Friend said the Hauberk is a nice salvage item that can net some nice money.