Need help getting icons to display in outline table

I am using Joe Chan's CSuperOutlineTable to create an outline table in
my app. I am trying to get the icons to appear for each item in the
table, but it isn't working.

I derived a class from CSuperOutlineTable called CPatternTable and I
derived a class from CEditableSuperOutlineItem called
CPatternCategoryItem. I am inserting CPatternCategoryItem objects
into the CPatternTable.

The ctor for CPatternCategoryItem looks like this (copied from Joe
Chan's sample code with the allegro stuff taken out and I hardcoded
the resID for the icon suite to be 1000 which is the value used in the
sample code):

CPatternCategoryItem::CPatternCategoryItem( LStr255 categoryName )
: mCategoryName(categoryName) {
::GetIconSuite( &mIcon, 1000, kSelectorAllAvailableData );

Size theSize = ::GetHandleSize( mIcon );
SInt16 resAttrs = ::GetResAttrs( mIcon );
OSErr err = ::ResError();
if ( err != noErr && theSize != 0 && resAttrs != 0 )
{
int i = 0;
}
}

I override the GetDrawContentsSelf function:

void
CPatternCategoryItem::GetDrawContentsSelf(
const STableCell& inCell,
SOutlineDrawContents& ioDrawContents)
{
if ( inCell.col == 1 )
{
ioDrawContents.outShowSelection = true;
ioDrawContents.outHasIcon = true;
ioDrawContents.outIconSuite = mIcon;
ioDrawContents.outIconTransform = kTransformNone;
ioDrawContents.outIconAlign = kAlignNone;
}
else if ( inCell.col == 2 )
{
ioDrawContents.outShowSelection = true;
ioDrawContents.outCanDoInPlaceEdit = true;
}

ioDrawContents.outTextTraits.style |= bold;
LString::CopyPStr(mCategoryName, ioDrawContents.outTextString);
}

In LOutlineItem::DrawCell, I added an OSErr variable to retrieve the
error from the call to PlotIconSuite for debugging purposes:

// If there's an icon, draw it.

if (drawInfo.outHasIcon && (drawInfo.outIconSuite != nil)) {
if (drawInfo.outShowSelection &&
mOutlineTable->CellIsSelected(inCell)) {
drawInfo.outIconTransform |= ttSelected;
}

if (drawInfo.prIconFrame.right < inLocalCellRect.right) { // don't
draw if rect is outside cell.
OSErr err = ::PlotIconSuite(&drawInfo.prIconFrame, (SInt16)
drawInfo.outIconAlign,
(SInt16) drawInfo.outIconTransform, drawInfo.outIconSuite);
}
}

This call results in err == -1000 (noMaskFoundErr). I can't seem to
find any documentation or info on why this would be returned. When I
run the sample code it works fine and the err here is 0.

BTW, I am using CW 8.3 on OS X 10.2.6 and the target is Carbon Debug

Any ideas?

TIA