I met the same trouble with you, but i use Smartkey SQL Password Recovery to help reset sa password, I think it also helps you well.

Reset sql password by Windows Authentication

If Built-in/Administrator is present in SQL , you can login with an ID which is member of Administrators group and reset password in SQL ....

ahmed_elbarbary.2010 (5/7/2012)

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Hi guys i install sql server 2005 standard edition sp1 original and after i install it and all services concerned about it successfully. i found problem this problem when...

dan-572483 (6/3/2012)

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Are there features in SQL 2008 (R2 or non R2) that don't work in the Evaluation edition , since it SQL Server is developed primarily for Server OS's? ...

I think the easiest and most efficient way to reset SA password is to take use of Smartkey SQL Password Recovery, which is designed to reset lost or forgotten user...

Thank you very much for your post, but i'm sorry that i can not suggest anything, and i have same question.