The below web services code has worked properly for me for over a year. We have updated our SharePoint servers, and now the below code throws an exception (at the bottom line of code) "Object reference not set to an instance of an object"

UserProfileWS.UserProfileService userProfileService = new UserProfileWS.UserProfileService();

userProfileService.Credentials = System.Net.CredentialCache.DefaultNetworkCredentials;

string serviceloc = "/_vti_bin/UserProfileService.asmx";
userProfileService.Url = _webUrl +  serviceloc;

UserProfileWS.PropertyData[] info = userProfileService.GetUserProfileByName(null);

EDIT: The service is still there. I browse http:///_vti_bin/UserProfileService.asmx, and the information for the service is still there, including the full description of the GetUserProfileByName call.

EDIT2: This does appear to be due to a change in SharePoint. I loaded a previous version of my software (known to be working), and it exhibits the same erroneous behavior.