If you close and then reopen X1 - does it restore correctly the position? Do you shutdown Windows while X1 is running?
In the data folder, in the file UIConfig.xml, there should be a section like this:
<ScreenConfigurations>
<ScreenConfigurations VirtualScreenWidth="2960" VirtualScreenHeight="1050">
<MainWindowMaximized>True</MainWindowMaximized>
<MainWindowX>0</MainWindowX>
<MainWindowY>0</MainWindowY>
<MainWindowW>1260</MainWindowW>
<MainWindowH>744</MainWindowH>
</ScreenConfigurations>
</ScreenConfigurations>
this is where the screen positions are kept for different resolutions and monitor combinations.
How does the section look for you? Does it change when you change X1 position?
Jogy