I am using X5, but I think you can use my technique in your version of VS.
I also ran into this problem. I think it has something to do with the 4:3 to 16:9 conversion. For me anyway, my solution was to keep my Project Properties video at the original (4:3), add the text/titles, render the project using SAME AS option (deselected NSPR), then I created a NEW project file and imported the converted video, created the Project Properties at 16:9 this time (still deselected NSPR), rendered, and it worked just fine.
Mostly, my problem was that I had to use the FX Cropping to remove some overscans (those lines at the bottom of the video from VHS scanning), and I chose not use the checkbox to keep the NSPR ratio (Non square pixel ratio) because I did not want my video to be stretched. That was me. I dunno about you.