sugarcrm not inserting email

Do you get an error starting like this when you are trying to get sugar to do an email broadcast?

for column 'description_html' at row 1

Sugar then lays out your email in an escaped format on the screen, if you do then this might help...

There are a few bits of information about errors like this occuring, and most of the fixes / hacks revolve around escaping single quotes and percentage signs, but I'm not convinced - I've had this particular install of Sugar successfully send emails that include both single quotes and percentage signs.

I noticed something strange in the escaped version of the html that was displayed, spaces where being converted to question marks in diamonds like this:

The spaces used to be   but somehow had become diamonds. When you view the source of the html email the spaces appear simply as spaces i.e. not diamonds and also not  

I deleted this mystery character and re-typed   for good measure; resent the email and presto - no more complaining from sugar.

This was / is happening in SugarCRM Version 4.5.1g (Build 1003) running on a windows 2003 server.

After thought

A possible explanation (or perhaps compounding cause): These errors happened when editing a template in Opera, having duplicated an existing template. Opera does not load the FCK editor, I am wondering if FCK editor leaves some special characters in the template markup that it converts to proper html entities on submit...