Informix-TP-XA

Hi, is there anybody having experience in using Informix via XA interface ? Informix TP/XA version 6.0 is installed on DEC Alphas, OSF/1 version 3.2. I call the XA-interface from Encina. An Encina function calls xa_open. I get the error message XAER_RMERR. According to my user manual the following may me the reasons for that error: 1 Unable to connect to online database server. 2 Internal communication error between frontend and online database server. 3 failure to open database (other than does not exist or no logging) The strange thing is that my call was already working. And now it does not work anymore. We didn`t change anything in the Informix installation since that time. To 3: The user (encina) under which the process is running has enough rights to open the database. To 1,3: I can access the database under the same user name from the same node with dbaccess. To 2: The error happens every time, not only once. Has anybody an idea what reason might be responsible for this error ? Petra