Looks like it is supported:
http://www.symantec.com/connect/forums/backing-sql-server-2005-express

There are mentions of it in the MSSQL 6.5 manual too.

On Wed, 30 Sep 2009, Patrick wrote:

> Do you have an application backup schedule covering the time in question?
>
>
>
> Regards,
>
>
>
> Patrick Whelan
>
> VERITAS Certified NetBackup Support Engineer for UNIX.
>
> VERITAS Certified NetBackup Support Engineer for Windows.
>
>
>
> <mailto:netbackup AT whelan-consulting.co DOT uk>
> netbackup AT whelan-consulting.co DOT uk
>
>
>
> <http://www.linkedin.com/in/patrickjosephwhelan>
> cid:[email protected]
>
>
>
> From: veritas-bu-bounces AT mailman.eng.auburn DOT edu
> [mailto:veritas-bu-bounces AT mailman.eng.auburn DOT edu] On Behalf Of
> J.Keating AT tachi-s DOT com
> Sent: 29 September 2009 23:43
> To: veritas-bu AT mailman.eng.auburn DOT edu
> Subject: [Veritas-bu] Backing up SQL Express
>
>
>
>
> Hello All;
>
> After recieving "operation not allowed during this time period(199)" errors
> while trying to backup an SQL 2005 Express database. I'm assuming that
> Veritas NBU 6.5.4 will not backup SQL Express.
>
> Would me my assumption be correct?
>
> Regards,
> John Keating
> Information Technology
> Tachi-S Engineering U.S.A. Inc.
>
>
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