onlog cannot read > 1 tape generated by ontape -c

Hi All, I am having a problem with ontape and onbar. I am using ontape -c to log to disk, and change the tape at < 2Gb. When I try and read the first tape created by ontape -c it works, but any subsequent tapes give the error : $ onlog -d ./log.tape7895_7925 INFORMIX-OnLine Logical Log display Software Serial Number ACN#J288408 Copyright (C) 1987-1996 Informix Software, Inc. Please mount tape and press Return to continue ... Bad tape - tape format not recognized. Why would this be so ? This is not true, as I have tested this and used the tape in question in a sucessfull logical recovery.. I need to read the log-tape-file heder to get the first log id number from it in order to correctly name a file after a dirty shutdown. If onlog is flawed, then how can I get information from a (second) log tape ( file ) regarding which logs are on it. Even the first log id would be usefull. Regards Graham Mitchell INFO : $ onlog -VINFORMIX-OnLine Version 7.24.UC4X6 Software Serial Number ACN#J288408 OS: hp-ux 10.20