Anyone have any experience with conditional installs with WI (ala VSI, Wise, InstallShield, etc...)?

I'm trying to set up an Install which will abort if a filename doesn't exist, (if it does exist the [INSTALLDIR] should be set to the location where the file was found.)

Per Wise Knowledgebase article 259127, I've setup the AppSearch, Signature, and DrLocator tables as follows:
(unlisted columns have been left blank)

AppSearch table:
Property = FILESEARCH1
Signature = RequiredFile1

Signature table:
Signature = RequiredFile1
FileName = npc.dat

DrLocator table:
Signature = RequiredFile1
Depth = 2

I've placed a textbox in the "ReadyToInstall" dialogbox
with property set to FILESEARCH1,
and can see that it is either (correctly) populated with the location of the file or '1' (if I change the filename so that it is not found.)

I've tried many variations in the General Information|Install Conditional entry but it never fails!

I've tried as the conditional (each line is separate attempt):
FILESEARCH1
FILESEARCH1 <> 1
FILESEARCH1 = 1
FILESEARCH1 <> "1"
FILESEARCH1 = "1"
FILESEARCH1 <> " " //space
FILESEARCH1 = " "
FILESEARCH1 <> "" // no space
FILESEARCH1 = ""

I never receive a 'type mismatch' or any other error message, the install proceeds as though there is no condition...

I've also created a simple VersionNT install condition (running on W98), with no luck (does Test release (in InstallShield & Wise) abort upon failed conditions?)

During Test Release (after Build Release), the first dialog box says its searching for existing "apps" (and displays FILESEARCH1 and FileRequired), but always proceeds. Should the test mode abort the install if not found?

Can someone please help or point me to an example which does a similar operation.

After this works, I presume my my next step would be to use a CA to set the [INSTALLDIR]...

My example here lists one file, the real install will have to check for either of 2 files (I've set FILESEARCH1, FILESEARCH2 AND FileRequired1, FileRequired2) similar to above.

Thanks for any input!!

P.S. I posted this on InstallSite.org yesterday, but that site isn't known for it's speed of replies (if someone responds at all)... < lol >