Upgrading R4 to R6 Client doesn't use Operating System Time Zone

We’re finding that clients that we’ve upgraded from R4.6.7 to R6.0.3 are retaining the R4 time zone settings and not picking up the (‘default’?) “Use operating system’s time zone” in the R6 client.

The only notes.ini variable we can find is “UseNotesTimeZone” which is designed to prevent Notes from using the OS time settings, but this doesn’t work in R6 anyway (I think it was designed for R5).

I did raise a support call with Lotus but they informed me that the only way to get around this is to uninstall the R4 client then install R6, which I feel a bit uncomfortable about when wanting to roll out R6 to the whole company.

Has anyone come up with a workaround for this?

Thanks, Mike