Software Deployment

We're beginning our upgrade from SMS 2.0 to 2003 SP1, and testing all the packages that we've configured in the new 2003 environment. However, on a few certain packages that have "chained" prerequisites, I'm seeing an interesting new problem. Here's the example:

PalmDesktop.msi requires that ISScript.msi is fully installed and "committed" before PalmDesktop.msi will run successfully. SMS 2.0 automagically ran ISScript.msi first, and PalmDesktop.msi second, and all was well. However, PalmDeskop.msi is failing in 2003 with the same configuration...

I set PalmDesktop.msi to make verbose log files, and they show that ISScript (the InstallShield Scripting Engine) is not installed! I setup ISScript.msi to make a verbose log, and it says it was successful; but the registry shows that it is no longer installed on the system.

So, my theory is that SMS 2003--which is Windows Installer aware--is wrapping up both MSIs into one transaction, so it can rollback upon failure. Is this now causing my failure since the prerequisite (ISScript.msi) is not fully committed when the PalmDesktop.msi package runs? (That would explain why both are de-installed upon failure as well.) Can anyone confirm if this is how SMS 2003 treats prerequisite Windows Installer installations?

And, if so, is there an easy way around it? We've got a handful of other apps with similar prerequisites, and they're all failing!

TIA--