process not reading script file

I am not able to get winscp to recognize the script file. It comes to the console prompt and just sits there.

command line
C:\Progra~1\WinSCP3\winscp3.exe /console sftp://testuser@sshftp.tstserver.com /privatekey=private_key.ppk /script=scrpt.txt /log=ftp.log

script file contains this
option batch on
option confirm off
prompt
bin
put SSHF_ACH_PAYRLR_NCFR5LN
bye

There's a minor bug in WinSCP preventing it finding the script file in working directory. Try to specify full path to the file.