Quad Warp Position Property
If you manually change the Position properties of Quad Warp (Top Left, Top Right, Bottom Left, Bottom Right) without turning on keyframes, and then save the project, the properties with be reset to "0.0" "0.0" when you later reopen the project.
If you turn on keyframing for this property, it will always add a keyframe at the very beginning of the clip (at the start of frame 1) with Position "0.0" "0.0", or if you had a keyframe already at the beginning of the clip, it will overwrite that keyframe with "0.0" "0.0" when reopening the project. All other keyframes after that seem to be unaffected.
Specs: Win7, Core i7, GT650M gpu, 8g ram