simonmic, 
Troublesome Transactions are the ones that slow you down, eg because:
- the journal entry is unknown/uncertain
- the entry is hard to produce by CSV rule or data entry UI
- the accounts are hard to recall, easy to confuse, or missing
- there's currency conversions
- many/repeating decimals
- corresponding adjustments to business-personal, household, client obligations...
- research and context switching needed
- etc
They're costly. Study and solve them one by one.
