Image in TreeTable cell not centered after upgrade to Vaadin 7.1

I have a TreeTable that consists of 2 columns. One column has an Image object in it and the other is a string. Prior to upgrading from Vaadin 6.8.x to 7.1, the image was centered vertically in the cell. Since the upgrade, however, the image is at the bottom of the cell(Image attached). There does not appear to be an option to vertically align the content of the cell with setColumnAlignment(), as that only gives options of left, center or right, so I tried to upgrade the CSS style to set the vertical-align attribute to “middle”. This does not seem to work either.

Here is my data source:

dataSource = new HierarchicalContainer();
dataSource.addContainerProperty("icon", Image.class, null);
dataSource.addContainerProperty("label", String.class, "");
dataSource.addContainerProperty("data", Client.class, null);

and my TreeTable:

table = new TreeTable();
table.addStyleName("striped");
table.setColumnHeaderMode(ColumnHeaderMode.HIDDEN);
table.setSizeFull();
table.setMultiSelect(false);
table.setWidth("100%");
table.setHeight("100%");
table.setAnimationsEnabled(true);
table.setContainerDataSource(dataSource);
table.setSortAscending(true);
table.setSortContainerPropertyId("label");
table.setVisibleColumns(new Object { "icon", "label" });
table.setImmediate(true);
table.addActionHandler(this);
table.setColumnWidth("icon", 30);
table.setColumnAlignment("icon", Align.LEFT);

and my Image:

Resource blueOrb = new ThemeResource("img/blue_orb.png");
Image orb = new Image(null, blueOrb);
orb.setWidth("12px");
orb.setHeight("12px");
dataSource.getContainerProperty(item, "icon").setValue(orb);

and here is what I tried in my custom stylesheet:

.v-treetable-cell-content {
    vertical-align: middle;
}

Any ideas?
13458.jpg

Any thoughts on this one? It worked without specifying in Vaadin 6.8, but something seems to have changed in Vaadin 7.1.

Update: I was able to work around this by padding the bottom of the affected cells.