Error Adding / Editing Topics

Am getting the follow error in 1.6 when adding or editing topics.

Topic Listing - /shop/administration/Topics.aspx

Webpage error details shown below.  In addition, when I add a new entry, there is a message displayed on the Dashboard, "Warning: You don't have localized version of topic [test topic] for English. Create it now"

Attempting to edit a topic results in an error similar to below.

User Agent: Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 5.1; Trident/4.0; .NET CLR 1.1.4322; .NET CLR 2.0.50727; InfoPath.1; .NET CLR 3.0.04506.30; .NET CLR 3.0.04506.648; .NET CLR 3.5.21022; .NET CLR 3.0.4506.2152; .NET CLR 3.5.30729)
Timestamp: Thu, 10 Jun 2010 02:43:08 UTC


Message: Invalid character
Line: 1
Char: 1
Code: 0
URI: http://<base url>/shop/ScriptResource.axd?d=KWUvF6SfsNCmTG6sp3ov5TC8JaAogzT1ptXuUD9pjwxyLkSLnu1GFQy47PTtxCcg0&t=ffffffffed6bd90b


Message: Invalid character
Line: 1
Char: 1
Code: 0
URI: http://<Base_URL>/shop/ScriptResource.axd?d=KWUvF6SfsNCmTG6sp3ov5TC8JaAogzT1ptXuUD9pjwycdXluuFjGg6dauzxLdctx0&t=ffffffffed6bd90b


Message: 'Sys' is undefined
Line: 53
Char: 1
Code: 0
URI: http://<Base_URL>/shop/administration/Topics.aspx


Message: 'Sys' is undefined
Line: 310
Char: 110
Code: 0
URI: http://<Base_URL>/shop/administration/Topics.aspx