If you buy a Kashflow account for more than one business, Dropbox integration doesn't work. The only workaround is to have two Dropbox accounts, which is inconvenient and not supported by Dropbox unless you sign up for a Business Account.
Kashflow puts your receipts into this folder:
Receipt number 1 for Business A is a different transaction to receipt number 1 for Business B, but they are in the same folder and get muddled in Kashflow
Kashflow should separate the receipts from the two businesses into two separate folders:
E.g. ../Dropbox/Apps/Kashflow/Business A/Receipts/
And ../Dropbox/Apps/Kashflow/Business B/Receipts/