According to my interpretation of the spec, for the following query: <sql:query ... startRow='3' maxRows='5'> ... </sql:query> You should see rows 3-7 (0-based, 5 rows). Instead, with the RI, I get rows 3 and 4.
The maximum rows returned didn't factor in the starting row value when getting the result set. I limit the result set my the maximum rows and in this case only the first 5 rows were included and with a starting row of 3 (0 based) you only saw rows 3 and 4 returned. The fix involved including the starting row to figure out how many total rows need to be retrieved. So with a starting row of 3, 8 rows total are retrieved in the result set and only rows 3-7 (0 based) will be displayed.