The space may be a problem. Boost.Serialization sticks the name directly into the XML, and <x:1 y:2></x:1 y:2> is bad.

It appears that this was indeed the problem - a rookie mistake. By removing any spaces I am able to drop name.c_str() straight in to ::make_nvp() with no problems. To provide further context, the reason I want to assign the tags dynamically is because I am using the Serialization library in a simpler fashion than that for which it was designed. I only wish to provide a means of outputting the state of a window and I have no desire to export in a format that can be reliably read back in to the same system. Thanks for all your help, John ******************************************************************** This email and any attachments are confidential to the intended recipient and may also be privileged. If you are not the intended recipient please delete it from your system and notify the sender. You should not copy it or use it for any purpose nor disclose or distribute its contents to any other person. ********************************************************************