[Printing-user-general] ESP GhostScript pstoraster filter error

A message in my error log states... 'Unable to convert file 0 to printable 
 
format forjob 23!'. 
 
The meaning of this message, according to the FAQ's at... 
http://linuxprinting.org/error_log-faq.html#q_3_12 is 
  
'...this is caused by not having the pstoraster filter included in ESP  
GhostScript, or not having applied the GhostScript patches in the  
pstoraster directory of the GNU GhostScript sources. You need to install  
ESP GhostScript or the patch starting with CUPS 1.1.15. 
It may also be necessary to compile ESP GhostScript against your current  
version of CUPS.' 
 
1) As you can see, I have ESP GhostScript installed... 
 
debian:/home/daryl# dpkg -l | grep esp 
ii  gs-esp         7.07.1-9       The Ghostscript PostScript interpreter - ESP 
 
If I have ESP GhostScript, which includes the pstoraster filter, how can the 
statement '...this is caused by not having the pstoraster filter included in 
ESP GhostScript' be true? 
 
2) Is GNU GhostScript an option to use in place of ESP GhostScript? 
   I tried to see if I have, or can install GNU GhostScript and I can't find it 
anywhere.  
   I'm assuming that GNU GS is not needed or recommended since I have ESP GS. 
 
Daryl...