Incomplete zip file - error message

[jennyk]

I keep getting this error. I have tracked it down to the following lines of code (line 2133 in VCLUnZip), last exception is raised:

if (not recOK) then { False = couldn't find the end central directory }
begin
if not Fixing then
begin
if (Assigned(FOnIncompleteZip)) then
FOnIncompleteZip(Self, FIncompleteZipMode);
if (FIncompleteZipMode = izAssumeNotAZip) then
raise ENotAZipFile.Create(LoadStr(IDS_INVALIDZIP));
if (FIncompleteZipMode = izAssumeMulti) then
begin { Just return and let them try again with the right disk }
raise EIncompleteZip.Create(LoadStr(IDS_INCOMPLETEZIP));
end;

The recOK is set false by ReadFromStream function call on line 2106, function is in in kpzipObj unit. The peoc: end_of_centralPtr variable is not being set correctly

I have no clue why and don't know where to go from here. Any ideas would be appreciated