MOD EDIT: While this doesn't appear malicious at first/second glance, and actually may contain useful information (I havnt tested it, and I wouldnt if you want my advice) this account is a first time poster on a 4 year old necro. Use this advise at your own risk.
I just had this problem recently, and found the solution, which wasn't included in any of the solutions I've found on the interweb. I'll post it on the very slim chance that it helps somebody.
It was connected with the installation of an old version of InstallShield (7), and somehow the registration of the IsProBE.tlb type library got deleted. Installing every version of the InstallScript engine I could get my hands on did nothing to help. Reinstalling IS7 would probably have fixed it, but in a catch-22 situation, I couldn't reinstall it until I fixed the 1608 error. I'll post the chunk of registry settings that I put together from an old installation and that resolved the problem. The GUID is going to vary according to which version of InstallShield you're using, so search for some Interface entries by name (e.g. ISetupRegistry4) - it's unlikely you'll be missing all of them - and see what the typelib GUID is. It needs to match in the TypeLib and Interface entries.
Don't mess too much with the registry unless you know what you're doing.
Change the file extension to .reg before executing - but be careful.