HTTP 400 - Bad Request

HTTP 400 - Bad Request

When using the get_records method this afternoon, I regularly get a 400 error either at fromIndex 1201 toIndex 1400 or fromIndex 14001 toIndex 14200. Can you shed some light on to what may be causing this issue? It's preventing me from accessing my data. If I make the request in my browser there is no error.

To the best of my knowledge, there is nothing else accessing the api, except potentially a Zoho -> Zoho sync (e.g. Campaigns, or Desk)

URI: https://crm.zoho.com/crm/private/json/Accounts/getRecords?fromIndex=1201&authtoken=#####&toIndex=1400&scope=crmapi

EDIT: This is resolved by putting a 1 second delay between requests.