Ambiguous column ( UNKNOWN tag: http://www.w3.org/1999/xhtml:column). (-324) If you encounter Informix "Ambiguous column" errors, take the following action: 1. Make sure the problem query executes in the Informix native dbaccess program. 2. Place backspaces in front of any underscores that appear in the query. 3. Use pass-through queries with fully qualified field names when MS Access is involved. 4. Make the following change to any Multi-Tier Rules book and test:A) Login to the computer that hosts your OpenLink server components. B) Use a text editor to open the oplrqb.ini file that resides in the bin sub-directory of the OpenLink installation. C) Locate the [Environment Informix] section that corresponds to your OpenLink database agent;e.g., [Environment INFORMIX2000]. D) Set the following parameter: DELIMIDENTY E) Save your changes and exit the file. F) Restart or reinitialize your Request Broker.Contact OpenLink Product Support, if the problem persists. Other known issues that contribute to this problem are the use of ADO or MS Access '97.