Since it seems like we are in different parts of the world I'll just share my data and the experiments I was going to ask you to help me with.

First off is the hit-miss charts I made ( I have already made them availible on the forums but I'll put the link in here aswell )
The first chart is no stacking penalty at all ( I'm leaving it in there )
The second is with stacking penalty.

Link: https://docs.google.com/spreadsheet/ccc?key=0AvYSJ6FRJlihdDI1NVpNdk5BQUh0bFphNktjLTU3R1E&usp=sharing

And here is a link to the complete data ( which I haven't shared before and only uploaded to google docs yesterday )

Link: https://docs.google.com/spreadsheet/ccc?key=0AvYSJ6FRJlihdFVJeWI5NVFUcmYwZERDQWhUSXZac2c&usp=sharing

The data is separated into a lot of sheets:

Heavy - Profile Dampening
Medium - Profile Dampening
Light - Profile Dampening
Scout - Profile Dampening

Heavy - Precision Enhancement
Medium - Precision Enhancement
Logistics - Precision Enhancement
Light - Precision Enhancement

Almost Everyone - Range Amplification
Gallente Scout - Range Amplification

All functions are intact in this spreadsheet so you can clearly see how stacking penalty is calculated.

Link to Aenigma's guide on stacking penalties in EVE: http://eve.battleclinic.com/guide/9196-Aenigma-s-Stacking-Penalty-Guide.html

Just a heads up; as most of you know DUST 514 is currently not calculating movement penalties on armor modules in the right order.

Exampel: Put 2 armor plates on a suit and mark your movement, then put a ferroscale ( 3:rd module ) on and you will see that your movement just increased. This is because the ferroscale is incorrectly calculated as being first in line for stacking penalty - meaning that stacking penalties are applied to the armor modules but not the ferroscale. ( since it is first in line. )

Now if DUST 514 incorrectly calculates 'negative precentages' in the wrong order it would be fair to assume that it could very well do the same while dealing with other modules. Such as 'Profile Dampeners' and 'Precision Enhancers'.

If the stacking penalties are calculated in the right order a medium suit with 1 ' complex profile dampener' and 1 'advanced profile dampener' would have a scan profile of 27.88 dB how ever if it is calculated in the wrong order it would end up being 28.18 dB.

Since a prototype scanner has a scan precision of 28 dB it should be easy to verify if the bug exists while dealing with these modules.

Feel free to send me in-game mails if you have any questions and / or want me to help out in any way.

( Oh and btw you can see that DUST 514 has stacking penalties on percentages by stacking 'cardiac regulators' or 'kinetic catalyzers' they'll experience the standard EVE pattern of stacking penalties. )