Problem: Loading A Flow Mesh Into XSI 6.5

[RealBill]

By default I can Load a Flow Mesh into xsi 6.5, but when i change the Frame Extension and Padding Size in the preferences in realflow such as (name_#.ext) (padding 3), I can't load the Flow Mesh and this is the error message (' INFO : RFMeshOp : D:New FolderameshesMesh000001.bin , can't open. Exiting Operator...)

by the way name of bin file in the error message is Mesh000001.bin but the real file name which I tried to load is Mesh01_001.bin

So what is the Problem.