The script test.scp is very simple:
option batch on option confirm off open sftp://user:firstname.lastname@example.org
Here's the command and output:
CMDPROMPT>"c:\program files\winscp\winscp.com" /script test.scp
Master password: Invalid access to memory
Check for updates says I have the latest version (4.2.7)
Win XP SP3
P.S. I had been getting the error where it claims there's no host. I added the -hostkey option to my open command in an attempt to get past that error and this symptom appeared just after that. This really *should* be much easier than it's been. It would help if there were some clues in the output about how to resolve the problems.