Parts of ToolBox missing, UPD from 2.2 to 3.0b7

[ferrosti]

I am updating from OTRS 2.2 to 3.0b7 and the weird thing is that only one half of the toolbox is shown.
I´ve got phone-ticket, mail-ticket, queue-view and status-view. Rest of the icons are missing.
The weird thing is, that this happens only when upgrading from 2.2 to 3.0b5 or 3.0b7 (b6 not tested). It works when upgrading to b4.

I have written a program that does the migration from 2.2 to 3.0 on DB side. Well, it´s rather a command wrapper using all the commands from the upgrade path. Very few are customized to our needs though. This is e.g. resetting our agent´s theme from *custom* to standard, nothing special.

When looking at the Sysconfig for Agent::Frontend::ToolBox almost everything is enabled. At least more than actually shown.

Does anyone have a hint?