<!–more–> – Not working.

Whenever I try to use the quicktag – !--more-- it doesnt work.
For example, I’ll type in blahblahblahblah !--more-- view my post, and then it shows blahblahblahblah (more…) but upon clicking on it just brings me to another page that has that blahblahblahblah (more…) it doesnt actually show the text I have after that tag.
Now, adding the !--nextpage-- tag works … But I cant seem to get more to work. Any help?.. Thank you very much for your time.