sima,
The only thing I can think of is that you may be using two different versions of the Fuzzy Logic Toolkit. Version 5.0 was a stand alone toolkit. Version 6.0 comes with the new PID 6.0 Toolkit. There may be file incompatabilities that you have found. Is this possible? Or are you using the same toolkit version on both machines?
Also, what operating system and version of LabVIEW are you using?
Randy Hoskin
Applications Engineer
National Instruments
http://www.ni.com/ask