High I/O Skew is typically due to an inefficient join. Be sure you have stats on the join and filter columns for both tables. You may need to look at step-level DBQL and/or Viewpoint Query Monitor to determine the step(s) with the issue and analyze the explain to see what the step(s) are doing.
The smaller the table, the less CurrentPermSkew is meaningful. I would ignore CurrentPermSkew unless MAX(CurrentPerm) for the table in DBC.TableSizeV is over 100MB or so.