Problems with delete lookahead

I have the following subprog:

open subprog disableLookahead

send 2 "disableLookahead: ENTER\n";

if (LOOKAHEAD_BUFFERSIZE != 0) {

dwell 10;

Coord[PARTPROG_CS].LHDistance = 0;

dwell 10;

Ldata.CmdStatus=1;

cmd "&%d delete lookahead", PARTPROG_CS;

sendallcmds; // Force commands from buffer

while (Ldata.CmdStatus > 0) {

send 2 "disableLookahead: IN LOOP Ldata.CmdStatus=%d\n",

Ldata.CmdStatus;

dwell 10;

} // Wait for command to execute

send 2 "disableLookahead: END LOOP Ldata.CmdStatus=%d\n",

Ldata.CmdStatus;

if (Ldata.CmdStatus != 0) {

call StopOnError(ERR_DELETE_LOOKAHEAD_FAIL, 0, 0, -1);

return;

}

dwell 10;

}

send 2 "disableLookahead: EXIT\n";

close

This command works without fail in nearly all conditions. I follow it with a similar subprog that defines the lookahead prior to starting a script in the coordinate system to ensure that the lookahead is set up.

The condition that fails is when I call this subprog after I have rebooted the powerpmac and have started running from a saved configuration. It never fails if I run it having downloaded the configuration from the IDE.

The failure condition is that it gets stuck in the loop waiting for the command to complete:

Port 2: disableLookahead: ENTER

Port 2: disableLookahead: IN LOOP Ldata.CmdStatus=1

Port 2: disableLookahead: IN LOOP Ldata.CmdStatus=1

Port 2: disableLookahead: IN LOOP Ldata.CmdStatus=1

Port 2: disableLookahead: IN LOOP Ldata.CmdStatus=1

Port 2: disableLookahead: IN LOOP Ldata.CmdStatus=1

Port 2: disableLookahead: IN LOOP Ldata.CmdStatus=1

Port 2: disableLookahead: IN LOOP Ldata.CmdStatus=1

Port 2: disableLookahead: IN LOOP Ldata.CmdStatus=1

Port 2: disableLookahead: IN LOOP Ldata.CmdStatus=1

Port 2: disableLookahead: IN LOOP Ldata.CmdStatus=1

etc.

Following a download however, I get the following:

Port 2: disableLookahead: ENTER

Port 2: disableLookahead: IN LOOP Ldata.CmdStatus=1

Port 2: disableLookahead: END LOOP Ldata.CmdStatus=0

Port 2: disableLookahead: EXIT

I would appreciate it if you could give me some ideas as to why the command never completes and indeed how I can debug the situation further.

Thanks

Graham