InfoPath Dev

im needing to update a sql server database with data from an infopath form so have to go down the web service route.

i have a web service that is working correctly and updating my database - however when i set up a web service form in infopath and enter the web service URL it finds the method and upon selecting it and clicking next i get this error: 

"InfoPath cannot use the selected Web service method to submit data because the method does not accept valid XML data"

what does this mean and how do i correct this problem?

does anyone have any working examples of such a web service that doesnt create this error?

thanks for any help 

Did you write your webservice in .NET, or on some other platform?

What are the datatypes of your webmethod's parameters and return value?

it was created in .net (visual studio) and simply creates a database connection, populate s a dataset and i want to populate the new row details from my infopath form where i will then do the add and update.

 What are the datatypes of the parameters to the web method?  string? int? XmlNode?

 Are you seeing this error when you set up the data connection, or when you try to actually use it?

my web service is accepting string datatypes, maybe im doing something wrong in the infopath form when im calling the web service.

im assuming i just map the parameters to my equivalent form fields?

 Did you remember to check "submit as a string" for each of the fields when you were setting up the data connection?

I get the same thing. However, here is my scenario.

I created a custom SharePoint web service that has 4 different methods.

I was able to successfully add them to my data connection and it works fine. However, when I convert these web services in the data connection to a udcx, I get the error: InfoPath cannot use the selected Web service method for receiving data because the method does not provide valid XML data.

Some articles referred to InfoPath 2007 using MSXML Core Services 5.0, which is one version behind the latest. And, there are several restrictions in regard to support for complexTypes.

Any ideas/thoughts?

Steve