XnView Stop working when there is/are big .txt files

[skyline021]

XnView 1.97
Win7 x64 Pro

Hi
XnView 1.97 is able to open up small .txt files.
However, when there is a big .txt file(The txt file was 1674KB and more) in a folder, XnViewer stopped working.

When I set off the Preview/Thumnail and made txt files not to show in XnVIew, XnView stopped working when I tried to Open up a Folder which has the .txt files.

thanks