Update termination error while doing PGR

Hi,

I got this error while doing PGR, please do suggest the dolution.

Update was terminated

System ID.... DPT

Client....... 900

User..... SDUSER

Transaction.. VL02N

Update key... 4BEAA8A2A6DA0609E1000000AC1107A7

Generated.... 12.05.2010, 18:38:55

Completed.... 12.05.2010, 18:38:56

Error Info... Update program: I/O error Error; function Update, RC= 4, key

Thanks,

Swapnil