macOS Preinstall script runs in Snowleopard even if we upgrade the software

[anandds]

Hi,

We have a simple package created using PackageMaker in Tiger. The same works fine in Snowleopard with no problems.

However, I see a difference in snowleopard that the preinstall script that should be run only when we freshly install the product is executed even if it is an upgrade. The install log indicate that the product is identified to be an upgraded (not a fresh install), but i see both the preinstall and the preupgarde scripts being run. I am actually trying to do an upgrade to the product and would not want the preinstall scrupts to be run in this case

Any one has an idea why this is so?

Thanks for any help,
Anand