Does anything break if you change Accounts numbers?

Hi,

Just a quick question - does anything break if I change the account 
numbers for an item in my chart of accounts which already has some 
allocated transactions?

ie Will the transactions be updated to reflect the new account numbers...?

The item I am proposing to change is a sales income category if this is 
relevant..

Cheers

Ed W

P.S. No doubt someone will have a really good reason for why this is a 
bad procedure from an accounting point of view, but please remember that 
some of us are using this as more of a management accounting tool than a 
legal invoicing tool and hence reposts and updates are actually useful 
features if they let us get out the info that we are after