When you click on loot, select the zone and npc.
LootDrops associated with this LootTable: 3 
Click on add and in this example lets say I am adding a new lootdrop and I want to set probability to 50.
It would save as 0 and I would have to then click on that 0 value which brings up the edit page and enter it there and then it would save.
Minor issue but I noticed it earlier when populating loot in a custom zone and wanted to fix it.
Personal preference is all.
I also changed my copy so when I add items to a loot drop I can set everything on that screen instead of adding a item then having to go in and change stuff like minlvl maxlvl charges and chance.
edit: I probably should be pulling from your daily dump more often but its not like anything is really broken and generating patches seems best off the svn revision.