I'm following your wiki for updating from J1.5 to J2.59 with Version:2.0.65.d729a82-a.
I updated via JUpdate and following these steps:
-install the joomleague 2.0.xxxxxx-a component package (.tar/.zip or by directory)
-execute the joomleague db table update script once by clicking on the button “Click here to do step 2 of 2 steps to finish the update.”
-execute the joomleague 1.6 to 2.0 update script once (the script will do some changes inside the database: project→serveroffset to timezone, migrate Ranking FES by removing the JL_ präfix, change timeformat in overall FES, migrate the picture pathes to the new Joomla 2.0 structure /images/com_joomleague …)
- recreate/check the menu links
- eventually reset/save frontend settings (ranking, …)
But the System doesn't import my old data base.
Do you have any advise? Could I change the name of the tables and copy them with phpmyadmin? Could it cause problems in the future?