The input and output encodings are not same - Cookie value decryption error.

I have an issue that I just noticed in which encrypted data that is stored within a cookie seems to get altered in a way in which it cannot be decrypted successfully if the length of the text is over 45 characters.  However, if the encrypted data is stored in a simple variable it can be successfully decrypted regardless of size.

Here is a code example:  I got the error in both CF9 Enterprise and CF11 Enterprise:

<!---Begin code example--->

<cfset plainText = "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa">

<cfset seed = "myseedvalue">

<cfcookie name="testvalue" value="#encrypt(plainText,seed)#" expires="never">

<cfset testvalue2 = encrypt(plainText,seed)>

<cfoutput>

  The encrypted cookie value:<br>  #cookie.testvalue#<br>

  The encrypted value outside of the cookie:<br>  #testvalue2#

</cfoutput>

<br><br>

A comparison of the two strings using the compare() method: <cfoutput >#compare(cookie.testvalue,testvalue2)#</cfoutput>

<br><br>

Decryption of the value outside the cookie yields:

<cfoutput>

#decrypt(testvalue2,seed)#

</cfoutput>

<br><br>

<br><br>

Decryption of the value in the cookie yields:

<cftry>

  <cfoutput>

  #decrypt(cookie.testvalue,seed)#

  </cfoutput>

  <br><br>

<cfcatch>

  <cfdump var="#cfcatch#" >

</cfcatch>

</cftry>

<!---End code example--->

The output of running this code is as follows:

The encrypted cookie value:

M7E;2R)*RK[:XK]^&>@ZX79Z44@VNAK6-_I^8?AW8FY*=KA*%!CP

The encrypted value outside of the cookie:

M7E;2R)*RK[:XK]^&>@ZX79Z44@VNAK6-_I^8?AW8FY*=KA*% !CP

A comparison of the two strings using the compare() method: 1

Decryption of the value outside the cookie yields: aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa

Decryption of the value in the cookie yields: An error occurred while trying to encrypt or decrypt your input string: The input and output encodings are not same.

Any insight is appreciated!