I just had a play with this on my site. That's when I noticed I had used a different script for this site than my others. It's from Dynamic Drive:
http://www.dynamicdrive.com/emailriddler/
Anyway, I tried the Enkoder. Very simple... Opened VSD's insert HTML tool and pasted the code straight from Enkoder into it. Works fine, looks like gibberish in the source code (just as with the D. Drive script).
Using the Web Dev toolbar though, I can see what the email address is (doesn't matter the script used – they all show)

Hopefully the bots just run through the source code and don't see anything of interest.
Why are you putting it inside the <p align="center"> script</p>
You don't need that with VSD.
Just paste the code and move it where you want it.

Phototwist, the <p> and what-not may be causing a conflict with how VSD wants to do things. All VSD sees is a paragraph – not a link. If you don't want to just drag the HTML box to where you want it, you may have to use a bit more code on this (in the HTML box, do the whole <style type="text/css"> and create a class for your <p>) so your styles will over-ride VSD. Not sure how well it will work with the paragraph within a script....
The simplest method does work