Description:
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using the mssql database extension, i am attempting to bind a parameter 
of type nvarchar(1999) to a stored procedure.  Everything works as 
expected except when the length of the parameter exceeds 256 chracters.  

In the case of a parameter length in excess of 256 characters the 
following message is returned by the DB server.  "Procedure or function 
'FunctionName' expects parameter '@ParameterName', which was not 
supplied."



Reproduce code:
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From manual page: function.mssql-bind
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this code won't reproduce the bug since you don't have access to my database...but i'm including it here so you you can be sure i'm not just getting a syntax error...

$sp = mssql_init("dbo.AddSnippet", $db);

$b = mssql_bind($sp, "@SnippetName", $snippetName, SQLVARCHAR, false, false, 120);
$b = mssql_bind($sp, "@SnippetDescription", $snippetDescription, SQLVARCHAR, false, false, 480);
$b = mssql_bind($sp, "@SnippetContent", $snippetContent, SQLVARCHAR, false, false, 1999);
$b = mssql_bind($sp, "@tagstring", $tagstring, SQLVARCHAR, false, false, 1999);
$b = mssql_bind($sp, "@TagUserID", $tagUserID, SQLINT4);

mssql_execute($sp);

Expected result:
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The stored procedure should add a record to the database and is designed 
to store nvarchar values of lengths up to 1999 characters.

Actual result:
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When the parameter length exceeds 256 characters, an error occurs.  

When the parameter length is <=256 characters, no error occurs.