problems with [if...] tags

[c-wheeler@c-wheeler.agelena.net]

I am unable to get [if...] tags to work in minivend. 
Here's an example:

.html code

		      <p>combo = "[item-field combo]"</p>
                [if-field combo]
		      <p>true</p>
                [else]
		      <p>false</p>
                [/else]
		[/if-field]

output when combo eq ""

combo = ""

[if-data products combo]    (why is this printed?)

true


output when combo ne ""

combo = "w103505 w103506 w103507 w103508"

[if-data products combo] 

true


output when combo == 0

combo = "0"

[if-data products combo] 

true

The conditional evaluates to true no matter what the value
of the string. I have tried all the other possibilities I
can think of after reading the docs and looking at the demo 
with the same result.

Thanks,

David