As most of you know, the ImgBurn installer sets SPTI acces by way of registry, setting the "allocatecdroms" value in HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon to 1. And as LIGHTNING UK! pointed out (and added warning to the installer) this may break LightScribe software.
However, this is due to bad programming on the LightScribe software part.
To explain this, I'll go a little deeper in what Windows actually does. Windows (by default since Windows 2000) sees a CDROM drive as a volume and therefore shares it by default.
So by default your CD-ROM is enabled for access by other computers (like \\computername\f$).
When "Allocatecdroms" is set to 1, the CD-ROM drives are restricted by only giving the "NT AUTHORITY\INTERACTIVE" user Full Access.
This means that only the current logged on user has access to the CDROM's, thus meaning that anyone else is denied access.
If LightScribe software is run as another user (for instance the Service it might use it started as NETWORK SERVICE or SYSTEM) it can't access the CD-ROM and thats why you get errors in those programs.
Setting the "allocatecdroms" value back to 0 fixes the LightScribe software again, but disallows users that do not have Local Admin privileges to Access CD-ROM's via ImgBurn.