Its definately not just s 'print to screen' memory problem. They are actually being truncated when they are read in.
What I want to do, as part of a large piece of scientific analysis, is search through is search through a table picking out any rows in that table that have a timestamp matching the timestamps in a different table. The timestamps are, by necessity, very precise.
I've got round it by reading the numbers before the decimal and after the decimal as different columns and then pattern matching - but its not very elegant...