Webpart error

I'm currently moving our product from a SharePoint 2007 WSS to a SharePoint 2010 Foundation. Most things have gone quite well. Migration of the content DB when without any problems at all. However one thing did happen that caused me some time to solve.A few of the webparts didn't work. I got an error in the webpart with an ID to the SharePoint Logs. Looking into the logs I found the following error message:

Error while executing web part: System.Xml.XmlException: Name cannot begin with the ' ' character, hexadecimal value 0x20. Line 1, position 19.

The webparts that didn't work where all of the same type. A Data web part where we use a web service call to fetch data from a DB. One of the parameters to the web service call is a "where" statement.
The web service ran fine. There was no problem with the where statement. It ran fine both through the web service and through a query window directly to the DB.

After some time working with this problem I found out that SharePoint 2007 and 2010 differs in one small area. In SharePoint 2007 I could write my where statement like this:

State < 70

State is a column in a table. The above would generate a SQL query looking like this:

SELECT * FROM table WHERE State < 70

However in SharePoint 2010 using &amp;lt; or (<) in a WHERE statement like that generates the above mentioned error message.

Knowing this it is obvious that in SharePoint 2010 the XML parser parsing the web service believes that a new tag is starting and finds nothing following the start tag (<) sign and hence responds with the error message.

My solution was to change the where statement to something like this:

State BETWEEN 0 AND 69

After that everything ran fine.