Sometimes Unable to find User from UserProfile Programmatically (C#) in SharePoint 2007

Question

Sometimes the code does not find the user from User profile. It simply checks the
profileManager.UserExists(userName[1]) and unable to fetch the user and executes the else part.
This issue is not regular. Most of the times it fetch the same user data correctly but sometimes fails.
What could be the possible reason of this and how to write it in the logs?
SPSecurity.RunWithElevatedPrivileges(delegate()
                 using (SPSite site = new SPSite(SPContext.Current.Site.Url))
                     //ServerContext object current site
                     ServerContext context = ServerContext.GetContext(site);
                     //UserProfileManager object to access MOSS user profiles
                     UserProfileManager profileManager = new UserProfileManager(context, false);
                     string[] userName;
                     userName = objUserUtility.GetCurrentUserLoginName().Trim().Split('\\');
                     WriteToLog(userName[1].ToString());
if (profileManager.UserExists(userName[1]))
WriteToLog("Entered Inside");
WriteToLog(userName[1].ToString());
else
lblUserExist.Visible = true;
                         lblUserExist.Text = "You are not configured in the Application";
Vishal Goyal

Answer 1

Vivek,
I am already using the below line code to fetch User Profile Properties.
UserProfile userprofile = profileManager.GetUserProfile(<userLoginName>);
Now this error comes User Not Found:could not load profile data from the database
Is this possible to track exact reason of this because this issue is not at all times.For same User the code  works fine but not all times.
My organization is using Sharepoint 2007 SP1.
Vishal Goyal