Using the latest jquery / tablesorter / widgets (as of Jan 18, 2016), using the pager widget, set pager_output to anything you want, so long as you include {totalRows}. Create two or more trivial tables with different id's and attach tablesorter to each id. Make sure the tables have a different number of rows. The pager will show the totalRows of the last-encountered table for every table rather than the appropriate number for each table.
The same is true for {filteredRows} when you including filtering.