In the navigator, drill down to your tables. Right-click on any table, and select "Count Rows".
A little pale-green popup appears in the lower right corner of pgAdmin that says "Table Rows Counted". But that's all it says... I.e., it doesn't actually report the number of rows in that table, as far as I can see.
Is there supposed to be some some other feedback somewhere, or am I misunderstanding the purpose of "Count Rows" (which I had assumed would just report the number of rows in the table)?