IDS2000 Aborting Long TX problem

We are getting some serious problems with our instance IDS2000 9.20.TC1 on Windows NT 4 Server SP 6a Have any of you seen this before ??? The database is using the TimeSeries datablade to capture financial info and populating the data into a live database. We also have a test database on the same instance (yes, yes I know...) that we are running a C program (MS Visual C) to populate a table with simple data i.e. not TimeSeries, via ODBC. We have loads of log space as described here:- Logical Logging Buffer bufused bufsize numrecs numpages numwrits recs/pages pages/io L-2 0 8 4776035 501490 458332 9.5 1.1 Subsystem numrecs Log Space used OLDRSAM 4776035 378148416 address number flags uniqid begin size used %used c049eb8 1 U-B---- 294 700003 225000 32361 14.38 c049ed4 2 U-B---- 295 c00003 25000 25000 100.00 c049ef0 3 U-B---- 296 c061ab 25000 25000 100.00 c049f0c 4 U-B---- 297 c0c353 25000 25000 100.00 c049f28 5 U-B---- 298 c124fb 25000 17031 68.12 c049f44 6 U---C-L 299 d00003 375000 368567 98.28 c049f60 7 U-B---- 284 600035 1250 1250 100.00 c049f7c 8 U-B---- 285 600517 1250 1250 100.00 c049f98 9 U-B---- 286 6009f9 1250 487 38.96 c049fb4 10 U-B---- 287 600edb 1250 1250 100.00 c049fd0 11 U-B---- 288 6013bd 1250 1250 100.00 c049fec 12 U-B---- 289 60189f 1250 1250 100.00 c04a008 13 U-B---- 290 601d81 1250 1250 100.00 c04a024 14 U-B---- 291 602263 1250 1250 100.00 c04a040 15 U-B---- 292 602745 1250 1250 100.00 c04a05c 16 U-B---- 293 602c27 1250 1250 100.00 The problem we are getting is that the database appears to be performing a long transaction roll back when hardly any of the log space is beng used - at last count, the C program load used about 70,000 pages within log no. 6. We havn't modified the LTXHWM or LTXEHWM which are set to 50 & 60 respectively Another funny, is that its not the C program that appears to be causing the roll-back, its one of the VP's that Informix is running:- Informix Dynamic Server 2000 Version 9.20.TC1 -- On-Line -- Up 1 days 00:00:48 -- 34240 Kbytes Message Log File: C:\\PROGRA~1\\informix\\ol_histinf.log 16:57:15 Fuzzy Checkpoint Completed: duration was 0 seconds, 58 buffersnot flushed. 16:57:15 Checkpoint loguniq 299, logpos 0x59f8c20c 16:57:15 Aborting Long Transaction: tx 0xc272e38 username: informix uid: 6 16:58:14 Fuzzy Checkpoint Completed: duration was 0 seconds, 58 buffersnot flushed. 16:58:14 Checkpoint loguniq 299, logpos 0x59f8e20c 16:58:14 Aborting Long Transaction: tx 0xc272e38 username: informix uid: 6 17:00:10 Fuzzy Checkpoint Completed: duration was 0 seconds, 60 buffersnot flushed. 17:00:10 Checkpoint loguniq 299, logpos 0x59f97aa0 17:00:11 Aborting Long Transaction: tx 0xc273548 username: informix uid: 6 17:00:14 Fuzzy Checkpoint Completed: duration was 0 seconds, 77 buffersnot flushed. 17:00:14 Checkpoint loguniq 299, logpos 0x59f9c2a4 17:00:15 Aborting Long Transaction: tx 0xc272728 username: informix uid: 6 17:01:42 Fuzzy Checkpoint Completed: duration was 0 seconds, 58 buffersnot flushed. 17:01:42 Checkpoint loguniq 299, logpos 0x59fad20c 17:01:42 Aborting Long Transaction: tx 0xc273548 username: informix uid: 6 An onstat -u reveals:- Userthreads address flags sessid user tty wait tout locks nreads nwrites c244018 ---P--D 1 informix - 0 0 0 1365 1645 c2445d4 ---P--F 0 informix - 0 0 0 0 174503 c244b90 ---P--- 6 informix - 0 0 0 0 5349 c24514c ---P--B 7 informix - 0 0 0 3703 6175 c245cc4 ---P--D 11 informix - 0 0 0 4 1 c246280 Y--P--- 13 informix HISTCL2 c44aa30 0 0 46756 10 6 active, 128 total, 14 maximum concurrent Sometimes, we are also getting this message from the onstat - command. When we get this, we can't move the database onto the next logical log, or, in fact, perform any onmode -l or -c commands. Informix Dynamic Server 2000 Version 9.20.TC1 -- On-Line(LONGTX)-- Up 1 days 00:00:48 -- 34240 Kbytes We have raised this with tech support, but havn't had any response back yet. All help much appreciated. Sean