'There is an input or output error' when trying to save a file

Hello friends, Has anyone seen this kind of problem on AIX 4.3.2 # ls > tmp1There is an input or output error. ksh: tmp1: 0403-005 Cannot create the specified file. # cat tmp1 : tmp1 is empty. no output # ls > tmp1 # cat tmp1 : now tmp1 is not empty.Xauthority .adsmrc .dbxhist .dt .dtprofile ....some more file names here # ls > tmp1There is an input or output error. ksh: tmp1: 0403-005 Cannot create the specified file. # cat tmp1 : now tmp1 is empty again Thanks in advance for any help. I know this not in any way a Informix problem. Regards Vinod Bhansali