check-column is set to display: none; in MultiSite

Hello-

I’m running 3.5.2 mutlisite and I just noticed that in the network admin users page (wp-admin/network/users.php) check-column has its display set to none:

<th scope="col" id="cb" class="manage-column column-cb check-column" style="display:none;"><label class="screen-reader-text" for="cb-select-all-1">Select All</label><input id="cb-select-all-1" type="checkbox"></th>

In class-wp-ms-users-list-table.php, I see this:

$style = '';
				if ( in_array( $column_name, $hidden ) )
					$style = ' style="display:none;"';

				$attributes = "$class$style";

				switch ( $column_name ) {
					case 'cb': ?>
						<th scope="row" class="check-column">

But I honestly don’t know what it is doing. The only thing I could think of was that it was somehow being hidden using the screen options, but there is no option to hide the columns.

Nothing has changed since yesterday when it worked fine.

Thoughts?

[Thread moved to multisite forum.]