Nabs wrotePeople who download with torrents seem to have that extra usage issue. Apparently, even if you pause your downloads, your uploads still work. Check it out, could be the issue.
I think this is only if you pause. If you stop the download, nothing should upload or download. Also, the scheduler should be for both download and upload, and not for download only. As in, the scheduler allows for seed-only hours in its schedule. Those should be disabled.
Another thing, guys (especially rtp), the amount consumed @IDM's website is much higher than what could theoretically be downloaded in those several minutes that a downloader may spend downloading after IDM ends unlimited nights.