Zero IOSB status

From: Ron Atkinson (oj_287_at_yahoo.co.uk)
Date: 03/31/05 

Date: 31 Mar 2005 03:12:05 -0800

When performing a QIO READVBLK + IO$M_LOCKBUF on an IP listening
socket, the QIO status is OK but the read IOSB status is returning the
value 0 instead of 1.

When I step through this bit of code using the pascal debugger it
returns 1 as expected.

In both cases the function works OK. What am I doing wrong ?