Late extract addition - IBU not changing?

I'm not seeing any change in IBU when working with an extract recipe that makes use of the late addition of some of the extract.  I am just looking for some confirmation that the problem is on my end, as I was pretty sure this used to work for me.

I create a new recipe - type: Extract.  Batch size: 5 gal.  Calculate boil volume based on my equipment profile.  Boil time:  60 minutes.

I add 1.5 oz of 5% AA hops for the 60 minutes of boil time.

Whether I add 2 lbs of 1.036 SG LME up front and 4 lbs with only 10 minutes remaining, or whether I add all 6 lbs of LME for the entire 60 minutes, I get the same IBU (36.7, Rager).  Even if I check the "add after boil" for some of the LME, the IBU never changes. 

Shouldn't I be seeing a variation in the IBU as I apply these various tweaks?  Or is there something obvious that I'm missing?

Thanks in advance.

The IBU changes for me with a late addition or after the boil checked.

Strange.  It won't change for me.

In fact, here's the "acid test" -- if I start with a blank Extract recipe, input the hops first (no grains specified at all), an IBU is calculated...even with no ingredients yet specified that would supply gravity points for the boil. 

Any grains added after that -- whether late addition, post-boil, or full-boil -- do nothing to change the original IBU.

Could this be due to some setting that I have enabled, or something with my equipment profile?  I am running v.2.1.02.

Any ideas appreciated.

I did your acid test and the IBUs change after I've added some grain and when I alter the addition time.

Not sure what to suggest for you because we are running the same version.

Fortunately for you, the IBU only shifts a small amount, like a max of 1ibu when starting with 30ibu, so you won't taste the difference.

Thanks for providing my sanity check, Skippy.

I can't explain why this worked, but I downloaded the installation file again (previous time was in May 2012), ran it, and now the IBU change seems to be working fine.  It's the same version, so I don't know why that would make a difference, but it has.

I'll chalk it up as a software oddity and move on, I guess. 

And you're correct that quite often the change in IBU is more "symbolic" than dramatic.  I just couldn't figure out (still can't) why it wasn't changing for me.