It's not seeding even when there are peers connected? I know sometimes they don't seed if there's enough available already. Like, if there's 1 peer and there's already 3.55 available.
If that's not the case, check in Options> Preferences> Transfer cap. Maybe the bandwidth cap is turned on for your ULs. Also check Preferences> Queueing. There's a place there if the box is checked it can limit your UL rate...... I know you can set DL/UL limits by R-clicking the utorrent icon. I'm not sure if that's the exact same setting or not. I'd check both places
Other than that I don't know. I'm not an expert