lexmark ipds comm error -- MIDRANGE-L

I'm trying to go live with a app printing to Lexmark Optra T 
with ipds card. Has worked fine for small batches. 1st 
big print (350 pages) and got error. Cannot determine cause:
I suspect a timing issue but don't know if printer or 400?
I setup using the Lexmark instructions with the ipds card. 
Cannot find msg id PQT3621 in Knowledge Base
tia
jim franz

PQT3621    Diagnostic              40   
 02/19/03   13:36:41   QPQCCOMM       QSYS        075B     QPQRMGR      QSYS   
 Message . . . . :   The session with device PQ ended abnormally.               
   
 Cause . . . . . :   The session with device PQ at RMTLOCNAME 10.0.1.177, using 
    
PORT 9100, ended abnormally.  The error code is 20, which indicates one of      
the following conditions: 20-39: A communications failure occurred. 40-59:      
An internal failure occurred. Recovery  . . . :   For error codes 20-39,        
check for problems in your network. After correcting the problem, start the    
printer writer to begin processing files again. If the problem continues,       
report it using the ANZPRB command. For error codes 40-59, start the printer    
writer again. If the problem continues, report it using the ANZPRB command.     
Technical description . . . . . . . . :   The internal message identifier       
(ID) is CPINT004.         

this is psf config
                                                            Sys
PSF configuration:   OPTRAPRT       Library:   QGPL            
                                                               
User resource library  . . . . . . . . . . . . . :   *JOBLIBL  
IPDS pass through  . . . . . . . . . . . . . . . :   *YES      
Activate release timer . . . . . . . . . . . . . :   *NORDYF   
Release timer  . . . . . . . . . . . . . . . . . :   *SEC15    
Restart timer  . . . . . . . . . . . . . . . . . :   *IMMED    
APPC and TCP/IP retry count  . . . . . . . . . . :   15        
Delay between APPC retries . . . . . . . . . . . :   90        
Automatic session recovery . . . . . . . . . . . :   *NO       
Acknowledgment frequency . . . . . . . . . . . . :   100       
Blank page . . . . . . . . . . . . . . . . . . . :   *YES    

this is device cfg

Device description . . . . . . . . :   PQ       
Option . . . . . . . . . . . . . . :   *BASIC   
Category of device . . . . . . . . :   *PRT     
                                                
Device class . . . . . . . . . . . :   *LAN     
Device type  . . . . . . . . . . . :   *IPDS    
Device model . . . . . . . . . . . :   0        
LAN attachment . . . . . . . . . . :   *IP      
Advanced function printing . . . . :   *YES     
Port number  . . . . . . . . . . . :   9100     
Online at IPL  . . . . . . . . . . :   *YES     
Font:                                           
  Identifier . . . . . . . . . . . :   011      
  Point size . . . . . . . . . . . :   *NONE    
Form feed  . . . . . . . . . . . . :   *AUTOCUT 
Separator drawer . . . . . . . . . :   *FILE    
Separator program  . . . . . . . . :   *NONE   
Printer error message  . . . . . . :   *INQ    
Message queue  . . . . . . . . . . :   *CTLD   
Current message queue  . . . . . . :   QSYSOPR 
  Library  . . . . . . . . . . . . :     QSYS  
Activation timer . . . . . . . . . :   *NOMAX  
Image configuration  . . . . . . . :   *NONE   
Maximum pending requests . . . . . :   6       
Print while converting . . . . . . :   *YES    
Form definition  . . . . . . . . . :   F1C10110
  Library  . . . . . . . . . . . . :     *LIBL 
Character identifier . . . . . . . :   *SYSVAL 
Remote location:                                  
  Name or address  . . . . . . . . :   10.0.1.177 
User-defined object  . . . . . . . :   OPTRAPRT   
  Library  . . . . . . . . . . . . :     QGPL     
  Object type  . . . . . . . . . . :     *PSFCFG  
Data transform program . . . . . . :   *NONE      
User-defined driver program  . . . :   *NONE      
Dependent location name  . . . . . :   *NONE