using wildcards in a filter for ListGrid (SmartGWT)

Question

I'm having the following ListGrid:

ListGridField eml = new ListGridField(EmlSearchItem.EMAIL, EmlSearchItem.EMAIL_TITLE);
emlGrid = new ListGrid();
emlGrid.setWidth("70%");
emlGrid.setHeight("60%");
emlGrid.setFields(eml);
emlGrid.setAutoFetchData(true);
emlGrid.setSelectionType(SelectionStyle.SINGLE);
emlGrid.setAllowFilterExpressions(true);
emlGrid.setShowFilterEditor(true);
emlGrid.setAutoFetchTextMatchStyle(TextMatchStyle. SUBSTRING);

according to the JavaDoc setting allowFilterExpressions to true should enable wildcards, like the * but I don't get any results.

for instance, I'm looking for a*com when I have an entry like 12343@chat.mysite.com inside my list won't return me any hits

is there another flag I need to set to get wildcards working in a ListGrid with filtering?