Upping importance. The bug appears to prevent me from using the Acquisitions modules> First, I created a Budget and Fund. I then went into Acquisitions and created a basket. Any attempt to add an item to that basket was met with the message "You can't create any orders unless you first define a budget and a fund.".

Lowering importance. The only account affected by this bug is the admin account ( i.e. borrowernumber 0 ). The subroutine CanUserUseBudget contains the line:

return 0 unless ($borrower and $budget);

which will return zero for anyone logged in as the super-admin, even though it is a valid account.

Not sure we should fix this. Lots of things in acq are dependent on the borrowernumber, because the system needs the information to figure out if the user is allowed to see a budget, fine, order tc. 
Maybe we should show a warning to stop using the superuser?

... where fine = fund. It's Monday :)

That's not a bad idea. Perhaps a system-wide warning at the top, that simply states you are using the superadmin account, and it is not recommended that you use it for day-to-day activity.

Marking RESOLVED--WONTFIX.

As a note, if you are using Plack and created the budget as a database user, it seems that you have to restart Plack before the message goes away, even if you're logged in as a regular user after finishing the configuration.