Error generating report job with the task name 'FSRM_Report_Task

Since this morning we have been having a problem with FSRM on Windows Server 2008 R2, it is no longer running storage reports (both scheduled and on-demand).

We get the following in the event logs:

Log Name:      Application
Source:        SRMREPORTS
Date:          09/06/2014 08:09:55
Event ID:      752
Task Category: None
Level:         Error
Keywords:      Classic
User:          N/A
Computer:      FILESERVER2.curriculum.riddlesdown.local
Description:
Error generating report job with the task name 'FSRM_Report_Task{3add1760-4e79-4141-baba-cb53391bef3e}'.

Context:
 - Exception encountered = Invalid argument: StorageType = '101'

Event Xml:
<Event xmlns="http://schemas.microsoft.com/win/2004/08/events/event">
  <System>
    <Provider Name="SRMREPORTS" />
    <EventID Qualifiers="0">752</EventID>
    <Level>2</Level>
    <Task>0</Task>
    <Keywords>0x80000000000000</Keywords>
    <TimeCreated SystemTime="2014-06-09T07:09:55.000000000Z" />
    <EventRecordID>42920</EventRecordID>
    <Channel>Application</Channel>
    <Computer>FILESERVER2.curriculum.riddlesdown.local</Computer>
    <Security />
  </System>
  <EventData>
    <Data>Error generating report job with the task name 'FSRM_Report_Task{3add1760-4e79-4141-baba-cb53391bef3e}'.

Context:
 - Exception encountered = Invalid argument: StorageType = '101'
</Data>
  </EventData>
</Event>

We have uninstalled and reinstalled the FSRM role service but are still having the same problem.

Anybody have any ideas?