Finally got an exception on that table when i tried to update something in the dwh rep. Which is a help.
11:23:21 [ERROR] Error (java.sql.SQLException) getting value for: 1/2 (java.lang.String: TABLENAME): java.sql.SQLException: [Sybase][ODBC Driver]Invalid cursor position
So it seems (my doing some rummaging around on google ) that the ResultSet.next() method was not called in the java application.. seems to be a common mistake. Time to give the developers a smack on the bum!
I love to know why something like this could truncate the whole table though.
Anyway, Ill keep talking to myself untill I figure it out, in the hope that it might help someone else in the future who comes across a similar problem .
Steve.