The default imaging format for CD-R discs, Joliet, allows you to use filenames up to 64 characters in length, including spaces. This error can usually be resolved by changing the imaging format to UDF 1.50. While this doesn't remove the restriction it does relax it quite a bit by bringing it up to 255 bytes (path 1023 bytes).
This setting can be changed by going to your QuickDisc preferences and opening up your "Disc/Imaging" options. Change the format from "Joliet" (default) to "UDF 1.50":
This setting will apply to all new projects going forward. To change the setting on a saved project you'll need to open the settings for that project while you're submitting it.