I just listed a woodworking writ for a "Trial by Fire" set and it ended up as a "Deadly Strike" set on the guild store. Here are the item links before and after:
item link before listing (trial by fire)
|H1:item:119682:6:1:0:0:0:65:192:4:208:13:16:0:0:0:0:0:0:0:0:58500|h|h
item link after listing (deadly strike)
|H1:item:119682:6:1:0:0:0:65:192:4:
127:13:16:0:0:0:0:0:0:0:0:58500|h|h
I'd say the issue we see is a wrong data type in the trading house data base.