I don't know why some editors are able to open them and others are not.
You are right about the character in those files and quite often I hear about it when someone tries to run a script which was created in windows notepad. They get this kind of error....
# ./test
: bad interpreter: No such file or directory
Here is a script which may help you get rid of the problem. For example, the text files are in /home/images...
Code:
#!/bin/bash
cd /home/images
for i in `ls *.txt` ; do
cat $i | tr -d '\015' > $i
done