It is possible that on fast dual processors and cluster networks the generation of the AFP-Cookies with the SYS(2015) function of Foxpro can deliver two identical values for different sessions. As a workaround you can generate an alternative Session-ID:

SYS(0) + _VFP.ProcessId + sys(2015)

SYS(0) = Name of computer (and user)
_VFP.ProcessId = Process ID
SYS(2015) = "unique" identifier

Alternatively you can use the IP number of the caller for own sessions but you must take into consideration that this won’t deliver unique values if the computer is behind a firewall.