StreamWriter & xml reading problem

Question

Hello.

I have this wierd problem when im writing to a text file with data from a array

I have this method:
        <sub>private void writeData()
        {
            // Open file
            StreamWriter writeData = new StreamWriter(saveMonsterSetBase.FileName, false);

            // Write all data from array to file
            for (int x = 0; x < MonsterSetBaseDataArray.Count; x++)
            {
                writeData.WriteLine(MonsterSetBaseDataArray[x]);
            }

            // Close stream
            writeData.Close();
        }</sub>

Which is trigged here:
            <sub>saveMonsterSetBase.ShowDialog();

            if (saveMonsterSetBase.FileName != "")
            {
                writeData();
            }</sub>

It works fine and opens my saveFileDialog

But after I save it I get a "file not found" on some other method I use

This is some of the method:
            _{// Opening txt file with location from XML
            StreamReader findMonsterStream = new StreamReader(@XMLmonsterLocation);}

I get the error monster.txt (XMLmonsterLocation) is not found

It looks like the writedata changes the local path because it says

File not found in the path where I saved the file

Example:
The application and monster.txt (XMLmonsterLocation) is saved in D:\

I then use the saveFileDialog (I save a file to for example C:\) and when I access my method where I use the XMLmonsterLocation it says file not found in C:\

So I dont know why

Hope you understand

The StreamReader reads from a xml file that looks like this:
_{<?xml version='1.0'?>
<config>
<monsterLocation>monster.txt</monsterLocation>
<monsterSetBaseLocation>MonsterSetBase.txt</monsterSetBaseLocation>
<monsterImageLocation>mobs\</monsterImageLocation>
<mapImageLocation>maps\</mapImageLocation>
<mapInfoLocation>maps\maps.txt</mapInfoLocation>
</config>}