I wrote a small intro to this, but didn't have the time to go into full detail -
http://thinktank.wpi.edu/article/140. If you can, please update it to include your findings.
Your scalar/vector problem indicates that you need to use the Pt by Pt version of the filter. One version just grabs a whole mess of data at once and filters it. The Pt by Pt version grabs it one point at a time and gives an output one point at a time.