Microsoft distributes Microsoft SQL Server 2005 fixes as one downloadable file. Because the fixes are cumulative, each new release contains all the hotfixes and all the security fixes that were included with the previous SQL Server 2005 fix release.
When you run a SQL Server Agent job in the context of a proxy account in Microsoft SQL Server 2005, the SQL Server Agent job fails. When this problem occurs, the following information is logged in the SQL Server Agent log:
2007-03-19 12:11:00 - !  CryptUnprotectData failed (1723). Unable to start execution of step 1 (reason: Error authenticating proxy <Proxy account name>, system error: Logon failure: unknown user name or bad password.). The step failed.
This problem is likely to occur if more than 10 SQL Server Agent jobs are running at the same time.
Note The proxy account may be disabled if the system is configured to lock an account after a certain number of attempts to log on fail.
SQL Server Agent uses the CryptUnprotectData function to decrypt the password of the proxy account. However, the SQL Server Agent job fails if too many calls to the CryptUnprotectData function are made at the same time.
This problem may occur if one of the following conditions is true:
More than 10 SQL Server Agent jobs are running at the same time.
Fewer than 10 SQL Server Agent jobs are running at the same time. However, the SQL Server Agent jobs have other operations that use the CryptUnprotectData function.
Cumulative update information
The fix for this issue was first released in Cumulative Update 3. For more information about how to obtain this cumulative update package for SQL Server 2005 Service Pack 2, click the following article number to view the article in the Microsoft Knowledge Base:
939537 Cumulative update package 3 for SQL Server 2005 Service Pack 2
Note Because the builds are cumulative, each new fix release contains all the hotfixes and all the security fixes that were included with the previous SQL Server 2005 fix release. Microsoft recommends that you consider applying the most recent fix release that contains this hotfix. For more information, click the following article number to view the article in the Microsoft Knowledge Base:
937137 The SQL Server 2005 builds that were released after SQL Server 2005 Service Pack 2 was released
Microsoft SQL Server 2005 hotfixes are created for specific SQL Server service packs. You must apply a SQL Server 2005 Service Pack 2 hotfix to an installation of SQL Server 2005 Service Pack 2. By default, any hotfix that is provided in a SQL Server service pack is included in the next SQL Server service pack.
A supported hotfix is available from Microsoft. However, this hotfix is intended to correct only the problem that is described in this article. Apply this hotfix only to systems that are experiencing this specific problem. This hotfix might receive additional testing. Therefore, if you are not severely affected by this problem, we recommend that you wait for the next software update that contains this hotfix.
If the hotfix is available for download, there is a "Hotfix download available" section at the top of this Knowledge Base article. If this section does not appear, contact Microsoft Customer Service and Support to obtain the hotfix.
Note If additional issues occur or if any troubleshooting is required, you might have to create a separate service request. The usual support costs will apply to additional support questions and issues that do not qualify for this specific hotfix. For a complete list of Microsoft Customer Service and Support telephone numbers or to create a separate service request, visit the following Microsoft Web site:
Note The "Hotfix download available" form displays the languages for which the hotfix is available. If you do not see your language, it is because a hotfix is not available for that language.
To apply this hotfix, you must have SQL Server 2005 Service Pack 2 installed. For more information about how to obtain SQL Server 2005 Service Pack 2, click the following article number to view the article in the Microsoft Knowledge Base:
913089 How to obtain the latest service pack for SQL Server 2005
You do not have to restart the computer after you apply this hotfix.
Hotfix replacement information
This hotfix does not replace any other hotfixes.
The English version of this hotfix has the file attributes (or later file attributes) that are listed in the following table. The dates and times for these files are listed in Coordinated Universal Time (UTC). When you view the file information, it is converted to local time. To find the difference between UTC and local time, use the Time Zone tab in the Date and Time item in Control Panel.