Special Characters cause error when setting Dell M620 BIOS Setup password via WINRM.

I have successfully scripted the changing of BIOS Setup passwords for M620 blades in powershell using WinRM. However.. when I attempt to set a new password using special characters, Wsman on the Dell M620 replies with a BIOS18 error and message stating "Invalid BIOS Password".

Entering a password containing special characters at the console works!?

Is there any work around to this?

Thanks!