Temp dbspace problem

Hi everyone, Running PeopleSoft on IDS 7.31UC2 and HPUX 10.20. We are running a cobol process with a particular SQL statement that's selecting distinct rows, and has three correlated queries...it's rather large so I won't post it. It runs successfully on other instances we have (two of which are identically configured in the way of dbspaces, one running 7.23UC4 and another running 7.3UC5). When the cobol executes the above mentioned SQL select statement it naturally begins taking up space in our two temp dbspaces. Each temp dbspace has 256000 pages. As the process continues I monitor the temp dbspace via onstat -d and it seems to be going along ok. A few thousand pages used from one, then a few thousand from the other. It seems to be evenly distributing the sorting load between these two dbspaces. Then, when both dbspaces are at about 59000 pages, the system stops using our first temp dbspace (tdbs1) and drains our second (tdbs2) down to zero, then giving us an Informix error -264 and ISAM error -131: "Could not write to a temporary file". Like I said, this works (with the same amount of data being processed) on our other instances, but it seems to be bombing out on our 7.31UC2 server. Has anyone run into anything like this before? I'm including my onconfig just in case someone can see something that I can't. Thanks so much for your time! Here's the onconfig: ROOTNAME root # Root dbspace nameROOTPATH /link_fsdev7/fsdev7_root # Device with root dbspace ROOTOFFSET 0 # Offset of root dbspace into device ROOTSIZE 30000 # Size of root dbspace (Kbytes) MIRROR 1 # Mirroring flag (Yes = 1, No = 0) MIRRORPATH /link_fsdev7/fs7_rootm # Path for mirrored root MIRROROFFSET 0 # Offset into mirrored device (Kbytes) PHYSDBS physdbs # Location (dbspace) of physical log PHYSFILE 63000 # Physical log file size (Kbytes) LOGFILES 99 # Number of logical log files LOGSIZE 1000 # Logical log size (Kbytes) MSGPATH /home/informix/logs_fsdev7/fsdev7.log # Sys log path CONSOLE /home/informix/logs_fsdev7/console.log # Sys con msg path ALARMPROGRAM /home/informix/log_full.sh # Alarm program path TAPEDEV /dev/null # Tape device path #TAPEDEV /dev/rmt/4m # Tape device path TAPEBLK 16 # Tape block size (Kbytes) TAPESIZE 8000000 # Maximum amount of data to put on tape (Kbytes) LTAPEDEV /dev/null # Log tape device path LTAPEBLK 16 # Log tape block size (Kbytes) LTAPESIZE 8000000 # Max amount of data put on log tape (Kbytes) STAGEBLOB # INFORMIX-OnLine/Optical staging area SERVERNUM 5 # Unique id corresponding to a OnLineinstance DBSERVERNAME fsdev7 # Name of default database server DBSERVERALIASES fsdev7_tcp # List of alternate dbservernames NETTYPE ipcshm,1,12,NET NETTYPE soctcp,2,50,NET DEADLOCK_TIMEOUT 60 # Max time to wait of lock in RESIDENT 1 # Forced residency flag (Yes = 1, No = MULTIPROCESSOR 1 # 0 for single-processor, 1 for multi- NUMCPUVPS 2 # Number of user (cpu) vps SINGLE_CPU_VP 0 # If non-zero, limit number of cpu vps NOAGE 1 # Process aging AFF_SPROC 0 # Affinity start processor AFF_NPROCS 0 # Affinity number of processors LOCKS 500000 # Maximum number of locks (pre- BUFFERS 30000 # Maximum number of shared buffers NUMAIOVPS 4 # Number of IO vps PHYSBUFF 32 # Physical log buffer size (Kbytes) LOGBUFF 32 # Logical log buffer size (Kbytes)LOGSMAX 100 # Maximum number of logical log files CLEANERS 15 # Number of buffer cleaner processes SHMBASE 0x0 # Shared memory base address SHMVIRTSIZE 40000 # initial virtual shared memory segment SHMADD 8192 # Size of new shared memory segments SHMTOTAL 0 # Total shared memory (Kbytes). CKPTINTVL 300 # Check point interval (in sec) LRUS 18 # Number of LRU queues LRU_MAX_DIRTY 2 # LRU percent dirty begin cleaning limit LRU_MIN_DIRTY 1 # LRU percent dirty end cleaning limit LTXHWM 50 # Long transaction high water mark LTXEHWM 60 # Long transaction high water mark TXTIMEOUT 0x12c # Transaction timeout (in sec) STACKSIZE 128 # Stack size (Kbytes) OFF_RECVRY_THREADS 20 # Default number of offline workerthreads ON_RECVRY_THREADS 20 # Default number of online workerthreads DRAUTO 0 # DR automatic switchover DRINTERVAL 30 # DR max time between DR buffer flushes (in sec) DRTIMEOUT 30 # DR network timeout (in sec)DRLOSTFOUND /opt/informix73UC5/dr.lostfound # DR lost+found file path CDR_LOGBUFFERS 2048 # size of log reading buffer pool CDR_EVALTHREADS 1,2 # evaluator threads (per-cpu- CDR_DSLOCKWAIT 5 # DS lockwait timeout (seconds) CDR_QUEUEMEM 4096 # Maximum amount of memory for any CDR BAR_ACT_LOG /tmp/bar_act.log BAR_MAX_BACKUP 0 BAR_RETRY 1 BAR_NB_XPORT_COUNT 10 BAR_XFER_BUF_SIZE 31 RA_PAGES # Number of pages to attempt to readahead RA_THRESHOLD # Number of pages left before next group DBSPACETEMP tdbs1,tdbs2 # Default temp dbspaces DUMPDIR /dev/null # Preserve diagnostics in this directory DUMPSHMEM 1 # Dump a copy of shared memory DUMPGCORE 0 # Dump a core image using 'gcore' DUMPCORE 0 # Dump a core image (Warning:this DUMPCNT 1 # Number of shared memory or gcore FILLFACTOR 90 # Fill factor for building indexes USEOSTIME 0 # 0: use internal time(fast), 1: get MAX_PDQPRIORITY 100 # Maximum allowed pdqpriority DS_MAX_QUERIES # Maximum number of decision supportqueries DS_TOTAL_MEMORY # Decision support memory (Kbytes) DS_MAX_SCANS 1048576 # Maximum number of decision supportscans DATASKIP off # List of dbspaces to skip OPTCOMPIND 0 # To hint the optimizer ONDBSPACEDOWN 2 # Dbspace down option: 0 = CONTINUE, 1 = ABORT, 2 = WAITLBU_PRESERVE 0 # Preserve last log for log backup OPCACHEMAX 0 # Maximum optical cache size (Kbytes) HETERO_COMMIT 0SYSALARMPROGRAM /opt1/informix73UC5/etc/evidence.sh # System Alarm program path TBLSPACE_STATS 1 ISM_DATA_POOL I