Uneven output levels using Adaptive Limiter

I am placing an adaptive limiter on the master output in Soundtrack Pro. The levels are fine when I playback the project, but as soon as I try to export, I get slightly higher levels on the left channel (about 1 or 2dB). When I check the exported file, the levels are indeed uneven. It seems to be a bug with Soundtrack Pro as I have had the same problem in all my projects. Has anyone encountered this issue, or know a workaround?