Connection issue Event ID 226

I am experiencing an issue connection to an RDS farm from another machine.  The client tries to connect then gets the generic error 'Remote Desktop can't connect to the remote computer for one of these reasons:' etc.

In the Microsoft-Windows-TerminalServices-RDPClient/Operational log I get the following message when the client does not connect:

Log Name:      Microsoft-Windows-TerminalServices-RDPClient/Operational
Source:        Microsoft-Windows-TerminalServices-ClientActiveXCore
Date:          6/9/2014 2:45:00 AM
Event ID:      226
Task Category: RDP State Transition
Level:         Warning
Keywords:      
User:          WBC\cwestwateradmin
Computer:      WBC-ITTS-01.wbc.local
Description:
RDPClient_TCP: An error was encountered when transitioning from TcpStateConnectingTransport to TcpStateDisconnected in response to 2 (error code 0x80004004).
Event Xml:
<Event xmlns="http://schemas.microsoft.com/win/2004/08/events/event">
  <System>
    <Provider Name="Microsoft-Windows-TerminalServices-ClientActiveXCore" Guid="{28AA95BB-D444-4719-A36F-40462168127E}" />
    <EventID>226</EventID>
    <Version>0</Version>
    <Level>3</Level>
    <Task>104</Task>
    <Opcode>19</Opcode>
    <Keywords>0x4000000000000000</Keywords>
    <TimeCreated SystemTime="2014-06-09T07:45:00.622998100Z" />
    <EventRecordID>12199</EventRecordID>
    <Correlation ActivityID="{59A63189-0267-44C7-A459-39D8ED500000}" />
    <Execution ProcessID="3856" ThreadID="2180" />
    <Channel>Microsoft-Windows-TerminalServices-RDPClient/Operational</Channel>
    <Computer>WBC-ITTS-01.wbc.local</Computer>
    <Security UserID="S-1-5-21-720231234-2037568477-3582021324-4396" />
  </System>
  <EventData>
    <Data Name="StateTransitionName">RDPClient_TCP</Data>
    <Data Name="PreviousState">1</Data>
    <Data Name="PreviousStateName">TcpStateConnectingTransport</Data>
    <Data Name="NewState">11</Data>
    <Data Name="NewStateName">TcpStateDisconnected</Data>
    <Data Name="Event">2</Data>
    <Data Name="EventName">TcpEventConnectionTimeout</Data>
    <Data Name="Error Code">2147500036</Data>
  </EventData>
</Event>

It's an intermittent issue but I would say 80% of the time the connection fails.

Any help appreciated