Hooray, I figured it out!
Hopefully this helps someone else out there one day:

I had to first:

my $thisItem;  #<-- this is imperative!

then:

$thisItem = $folder->Items($i);
if ($thisItem->{'Unread'}) {
...etc...

[download]

and replace every instance of

$folder->Items($i)

with

$thisItem

Then it works like a charm!!
Also don't forget to save changes at the end of changing each email:

$thisItem->Save();

Yay!

In reply to Re: Using Win32::OLE to set categories in Outlook 2007 by jdavidson
in thread Using Win32::OLE to set categories in Outlook 2007 by Anonymous Monk

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