some of my data gets re-align every time i re-add it in within the QGIS Table of contents ( like a good 5-10 feet off). I have no idea what could be the cause, I may have the given layer in a different projection compared to the basemap but i don't think that is the case. suggestions?
If you know the CRS of your vector layer then add that to a new map document. Next, open the layer properties and define the CRS, if necessary. After that, make sure that on-the-fly projection is enabled in the document properties, then add your basemap. All should line up if your basemap's projection is known and/or if you are using a served raster.