I am curious that you state in this post to migrate Joomla from 1.5.26 to 2.5.x first, then VM, yet the VM migration guide at Dashhelp states to migrate VM first then Joomla? Which is actually easier and more successful?
I am surprised VM developers have not written a migration script that saves all settings for import into the new install.
@Shibumi: you mean like this one
? Anyway they coded a component that handle its own migration process quite well in real life (only my experience), and wrote an exact if simple howto
@Shibumi and FrankA
Migrating Joomla first was also recommended by jeronimo078.
Now the two times I've done this way have resulted in no Shoppers and invoices data migrated to Vm2.
Migrating VM first solved this both time.
Have posted a detailed memo that is based on paulyap2k's but takes account of our own successful (so far) migration to VM2 and Joomla 2.5: http://web.lliseil.fr/e-commerce/38-migrer-sa-boutique-vers-virtuemart-2
(detailed steps are in plain English)
stuffdone link=topic=102783.msg380248#msg380248 date=1360780802]
I also have had systematic issues when using jupgrade (more precisely various structural inadequencies into the ASSETS table, which is Joomla core table). We have finaly solved them using ikajaste's assetweaver but only partially!