DLC for F2P Games "Missing Base Game"

I don't supposed anyone knows how to get SG's sync function to recognize F2P games, eh? I've been trying to enter a giveaway for a starter pack for Tribes Ascend, and it keeps telling me I don't have the base game (and sure enough, it's not listed on my sync list). Weird. Someone else mentioned that they played it for a bit, then re-synced, but that doesn't seem to be working for me as it did for them. Can't figure out how to get that sucker to show on the list. Any ideas?