If you are like me, you relied on views to create your menus and lists. Unfortunately, you won't be able to reuse your D4 views if you go straight from D4 to D6.
Let me clarify. There is a feature in Views2 that allows you to convert your old views. I tried this but is didn't work. I got the following message:
user warning: Table 'idcm6.view_exposed_filter' doesn't exist query: SELECT * FROM view_exposed_filter WHERE vid = 3 ORDER BY position ASC in /home/idcmi/idcminnovations.com/html/sites/idcminnovations.com/modules/views/includes/convert.inc on line 443.
I can't say for sure if the following idea would work but maybe, if you walked through your upgrade and included view updates along the way, maybe it would help. I don't know.
Wow, what a change. Once you get the hang of it, the new Views2 is pretty cool. There are some tutorials available to help. Start here http://drupal.org/node/395064 with an introduction. The views help can also be found at http://views-help.doc.logrus.com/. Lullabot has new training video out called "Learning Views for Drupal."
D4.6.8 to D6.10: Views1 for D4.x to Views2 for D6.x