I tried the below mentioned fix for the spacing issue to no avail so I emailed the developer. I got the following reply very promptly and it worked like a charm. Highly recommended.

In the .php file,replace:

$title = $prefix.$title;
with
$title = $prefix.' '.$title;

Great work. Work as i wanted.

Simple to install and setup. Very helpful to add page titles.

One issue, if I put "|" then space after it, the space doesn't show up. Ideas?

First off - excellent plugin. To be honest I was way too lazy to come up with a simple and beautiful solution like that myself - is why I searched for it and installed it in the first place. And the whole process took less than a minute too so that already proved me right. Anyway - I set up a prefix and it was indeed (just) a prefix. Meaning I wrote something like "domainname.com" and in the end the title looked like "domainname.comMain" so I added a " - " in the prefix box which turned it into a "domainname.com -Main" - so for some reason the box didn't want me to end with a space. If you experienced the same problems and if you want it to be like " - " as well, here's a simple step how to fix that issue. Go to your joomla root web directory and cd into directory "plugins/system" open the file seftitleprefixsuffix.php with an editor and add the variable $spacer = ' - '; (somewhere with the other variables)
then you just modify the line
$title = $prefix.$title;
to
$title = $prefix.$spacer.$title;
save the file, change the prefix in administrator back to "domainname.com" and voila ;D

I just installed this plugin.
This plugin allow you to added prefix/suffix in your page title..

The Page Title will be somekind like:
[prefix][article title][suffix]

it really does take the article title not the article alias.. So it's excellent..

Recommended ^^