Inno Setup - Parameter "ValueData" is not a valid value

Question

I'm trying to compile an installation package for a networking monitoring utility called PRTG. I am basically doing this:

http://kb.paessler.com/en/topic/60635-how-can-i-silently-install-a-remote-probe-in-my-network

except, I'm trying to automate it.

Everything works except for one Registry key:

[Registry]
Root: HKLM; Subkey: "Software\Wow6432Node\Paessler\PRTG Network Monitor\Probe"; 
    ValueType: dword; ValueName: "Password"; ValueData: "8b9a69b9"

I've tried Hexadecimal and Decimal and neither worked. Oddly, when I remove the above characters and replace it with any other value the installer will compile.

Help me Obi-One Kenobi!