Question : PSCP -- transfer from Windox box to UNIX box

We have scheduled 5 files to be moved to a unix box in an interval of 10 mins each.
We sometimes get the following error , not always though and one particular file fails the remaing files are moved after that. the file that files is nt specific.. something randomly but it has this error when failing.

Error :

The servers Host key is not cached in teh registry . You have no gaurantee that the server is teh computer that you think it is.
The servers rsa2 finger print .............
.................
Connection abadoned.

Answer : PSCP -- transfer from Windox box to UNIX box

are the ip addresses fixed or are changing for the sending and receiving systems?