>Recently ran into problem at customer site where after a recent Microsoft Update, every time our application tries to access certain ActiveX controls (e.g. comdlg32.ocx -- common dialog control), it triggers the running of a setup program or an update msi. The problem sounds vaguely familiar -- I do remember hearing about this sort of issue, and the problem being something about one of the registry keys (normally containing full path to the OCX) either ending up blank or containing some sort of gibberish. I also vaguely recall that one of the fixes for this was to correct the problem with some of those keys. Does anybody remember much about this, or have links to page that describes the procedure to correct for this problem?
>side note: It does seem peculiar that when the one of the update msi file is triggered (it's in the C:\Windows\Update folder), Windows complains that it is from an unknown source -- which I find peculiar, since I've not seen an update MSI file from Microsoft that hadn't been digitally signed as coming from Microsoft (at least recently).

Maybe http://doughennig.com/papers/Pub/Jun98.pdf ?