I have a user who accesses our 2008R2 RDS server from an XP machine with dual monitors. I have enable the "/span" switch on her connection so she can utilize both monitors. She also accesses the RDS server from her laptop which has a single monitor.
The problem arisses when she moves a program over to the second monitor while in /span. Then later she tries to access that same program in RDS from her laptop and the program opens in a location she can't see on that second monitor.