Aaron Russell's dashboard

I've been a bit lazy and not imported my bank statements for a a few months. Therefore whenever I've marked an invoice as paid my bank account according to Freeagent has had many credits but no debits, resulting in an artificially high balance of many, many thousands.

However, I recently imported all backdated bank statements and matched the invoice payments to their correct credits on the statements. My bank account is now accurate with an up-to-date list of credits and debits, but the graph (on both the dashboard and bank account summary page) has gone haywire - it has no reflection on the actual figures at all.

Any ideas what might be going on here?