It's possible that you've enabled iCloud to import your photo stream to Aperture/iPhoto. Because of the whole "can't selectively upload from Aperture/iPhoto library" thing, this means Picturelife will grab photo stream photos via Aperture/iPhoto.
It's also possible that the photos were already queued for upload before you disabled Photo Stream (in either Preferences > Folders, or in your Aperture/iPhoto library - in which case, unless you caught them in Preferences > Account > "Show Local Library" > Uploading, Picturelife uploaded them to your account.)
You have a couple of options:
- Make sure Photostream is not selected in Preferences > Folders on the desktop app
- If you import your Photostream to iPhoto or Aperture, disable shared photostream imports in the program's preferences menu. This article explains the steps in Aperture (they are the same in iPhoto): http://support.apple.com/kb/PH11966
- Use one of the selective upload workarounds mentioned above.
If after doing the above, you still believe Picturelife is grabbing your photo stream, try to find the photos in your Picturelife account. Open Albums in your web account and select "Aperture library" or "iPhoto library" from the "Show" drop down menu at the top of the Albums page. From there, search for the word Photo Stream on the albums cover photo.
This article explains how to delete unwanted albums from your account on the web: How to delete photos, videos, and / or albums from Picturelife on the web