Hi Martijn, thank you for being so involved with the community!
I have a problem, though: although they are registering as keys and raising the keycount, the arrow keys (and the navigation and insert and delete keys) are not showing up in the heatmap.
Thanks for your time! Groetjes 
Please state your OS and other system details, I’ve tested the key mapping on most systems, but it could be different on yours.
I run 32 bit Windows 7 with Whatpulse v2.1. Intel t9500 with an ATi Radeon HD 4650M.
For me the same happens. None of these keys are counted in the heatmap:
My OS is Windows 7 32 bits; WhatPulse version is 2.1.
I have looked into the database file searching when was the last date it recognised the key, and I think it occurs since 2.1b1 (in 2.0.4 it was OK).
PD: I can give you more information related on how is working on my computer: The key ids for those keys have changed comparing version 2.0.4 and previous, and 2.1:
WP <=2.0.4 - key up id is 16777235.
WP >2.1b1 - key up id is 16781913.
That could be it. Since WP keyboard image doesnt have the extra letters as are required around the world.
But I do remember that the old whatpulse 1.7 did register scandinavian letters also since it did not use any heatmap as 2.X are using.
Running in win 8 x64 with 2.1.1
This bug has been there since at least 2.1b2. I get it on both Win7 and WinXP, and I use normal US layout keyboards. I was mashing the the keys to make them change colour, and at one point the 10 keys all changed to red, but they always show Pressed 0x:
Also, since there’s no numpad, why not have numpad numbers, arrows and symbols count towards their heatmap counterparts? My numpad enter already counts towards the heatmap enter.
Apart from that, 2.1.1 is working perfectly so far. Nice work guys!
Sorry to thread bump a month later but I recently installed WhatPulse and noticed my “Q” key is not being counted on the heatmap, along with my arrow keys, numpad, INS, DEL, HOME, etc. I’m working on a laptop with a 104-key Rosewill RK-9000BRI keyboard (standard ANSI layout) and use the numpad extensively throughout the day. Heatmap on my desktop at home has the same issue with ‘Q’ showing 0 presses, but keystrokes are still being counted towards my total.
Laptop is running:
WhatPulse 2.1.1.
Windows 7 Home x64 (SP1)
Desktop:
WhatPulse 2.1.1.
Windows 7 Ultimate x64 (SP1)
All in all, neat program and I love getting statistics on my computer usage - just curious as to why the heatmap seems to be inconsistent.
same probleme here. but i have also G1 G2 G3 G4 G5 G6 buntons. can jou make that count in the next version? sorry for my bad englische 
i am running on win8 professional 64x bit
keyboard: logitech gaming keyboard G105
whatpulse version: 2.1.1
thank you,
thom