Harvardfan. I'm not sure what connection the Avro Arrow or any other aircraft has with scenery. If you stick with the installation method described in this tute you shouldn't go far wrong. http://www.simviation.com/acinstall.htm
Most FS2000 aircraft will work well in CFS2. Many early CFS2 aircraft are actually FS2000 designs with DP files. This article might explain your problem. http://www.simviation.com/lair/aliasing1.htm