[otrs] Zero Sized Reply

Morning all, Every couple of days we seem to have an issue with logging into OTRS first thing in the morning. This morning when we tried we got the following error:- The following error was encountered Zero Sized Reply Filter device did not receive any data for this request If I restart the OTRS service I'm able to login again. Has anybody else experienced this? OS is Open Suse 11.1 and OTRS version is 2.4.4 Many thanks, David