we are using Informix Client-SDK 2.70...
There's a big statement over 600 lines, in Informix client-sdk 2.70 we get an error or access violation in iclit09bW.dll.
If i'am using Informix Client-SDK 2.90 it's all right, but we have no choise.
There are some settings for ODBC with Client-SDK 2.70 to handle extreme big sql statements?
I never encountered this problem but this is something you may want to check. If you open setnet32 you'll find an environment variable called FET_BUFF_SIZE, click it to highlight it and put 32767 in the "Edit Environment Variable" box.
Pretty sure I got this info from PeopleSoft Tech Support years ago, perhaps it may apply to your situation.