I found a job at a company that seems to work with technology. I've sent the HR department (hr@optoma.co.uk) two times my CV in "txt" format, and although the file is about 1KB they could not open it. (I know that in certain circumstances the text could display as garbled but they didn't say that they were able to open it.) There are guides on the internet on how to open a txt file using MS Office if that is what they use.
http://www.optoma.co.uk/careers/vacancy/2229/Account-Manager
I wonder if that is a honest HR response or none of the managers could open such a file.