Interbase - transactions that disappear then reappear

Greetings. I have a data-entry web application that runs on: PHP 4.0.5 Interbase 6.01 (open source) Apache 1.3.19 Windows NT Server The users report an unreproducible problem: 1. A record is entered. 2. Some time later (hours, days, weeks), user wished to update record. Yet, record does not appear in database. 3. User re-enters record (with a strange sense of deja vu). 4. Some time later, both original and new record appear in database. My PHP application does the following for every transaction: 1. connect 2. run SQL statement (either insert, update, delete, or select) 3. disconnect The reason I disconnect is to auto commit. During development, the ibase_commit() function did not work and I was having problems issuing a 'COMMIT' statement directly. I am stumped, because predictably, I cannot reproduce this problem. During testing, every transaction I have entered is available. I welcome any advice or suggestions. Thanks Jeffery Cann