The character 152 (˜) is invisible in the Query Editors of SSMS 2005 and SSMS 2008. You can see it from this post. But, if you copy the following TSQL code to the SSMS Query Editors, the character will disappear. If you execute the query, you will be able to see it from the result. If you measure its length, it will be 1.
It is a matter of how the editors handling character 152 in the Courier New font. Both Query Editors of SSMS 2005 and SSMS 2005 set the default font to Courier New font. Both do not display the character.
The text editors notepad, notepad2, and notepad++ will overlay the character to the next following character if the fonts are set to Courier New.