NullPointerException when calling ResultSet.absolute(int)

Hi there!

I've installed PostgreSQL-7.4 on my system and I am really impressed
about the features and stability PostgreSQL provides. Its an excellent
piece of software!

However I've written a Swing-Table which displays data directly from a
ResultSet, and this works great if I select all rows, but when doing a
more specific search I get a NullPointerException:

Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException
at org.postgresql.jdbc2.AbstractJdbc2ResultSet.absolute(AbstractJdbc2ResultSet.java:184)
at CATableModel.getValueAt(CATableModel.java:88)
at javax.swing.JTable.getValueAt(JTable.java:1852)

Any ideas what could be the cause?

Thank you in advance, lg Clemens

btw. is there a more intelligent way to find out how many lines have
been selected than starting two queries where the one query just
queries the row-count?
I did not find any better solution, but for complex queries this is
really inefficient :-(