Which NBU binaries did you install on the client?
Did you use the 64-bit NetBackup Windows X64 install media?
I've seen status 13 when 32-bit binaries were installed.

What operating system exactly is the client? Are you sure you put the correct client software on the client?  If this is an Itanium-64 processor you will need a IA-64 client.  There are a few things to consider but lets start with the specifics on OS and hardware paltform.  

The Client is Microsoft Windows Server 2003 R2 - Standard x64 Edition - Service Pack 2. Under device manager it lists an ACPI Mulitprocessor x64-based PC). Under Processors it has eight - Intel Xeon CPU x5365 @ 3.00GHz.

I installed Verits NetBackup Client 6.5. I ran the setup.exe under the x64\PC_Clnt\x64\ folder after extracting locally.
I guess I'm not 100% sure I have loaded the correct client. After extracting the .zip file, there are about 5+ different setup.exe files or Veritas Netbackup.msi files...   it makes it hard for me to feel sure I loaded the right one.

I first tried pushing the 32-bit client from my server and that came back with an error. Would attempting to push the 32-bit first have left behind some ugly registry modifications that might need cleaning up?

I do not know how to tell which NBU binaries I installed.

I think what Marianna means is that your master is 6.0MP5 (or was that a typo?), and your master needs to be at the same revision as your client or higher.  Your client cannot be higher than your master server.

This is exactly where I was headed with my question.  Take not that the 6.0 version does not have a 64 bit client unless the hardware platform is the Itanium,  then you need the IA-64 bit.  Otherwise you will need to install the 6.0 32-bit windows client and patch it appropriately. 

Dont forget to mark the solution if you got what you needed.

ok....    am I hearing that in order to backup a 64-bit (that is NOT Itanium); I need to upgrade my Master server to 6.5?
I do not recall seeing a download for a 64-bit Windows 6.0 client.

...but the 32-bit version of 6.0 would not install on my 64-bit Windows server. It was not that cooperative.  :o(

The 32-bit client is what you should be using on your 64-bit server in NetBackup 6.0 (again unless the hardware platfrom is Itanium).  So please elaborate on "not that cooperative".  This wasy we can try to determine what problems you are having with the client install. 

Another point is are you trying to isntall the client software with a push from the master or are you installing the software locally fro media.  I have found (especially in older versions)  trying to push the software from the master to Windows clients is not always smooth and sometimes you're better off installing locally from media.

there is this
Maintenance Pack NB_60_5_M.winnt.x64.exe provides fixes to the Veritas NetBackup (tm) Enterprise Server / Server 6.0 on Windows XP/2003 X64 server and clients. It also contains fixes for NetBackup Add-on products and Database Agents.

seer.entsupport.symantec.com/docs/290388.htm

but yo have to get the 6.0 from file connect ( they don't open the base cd's to just anybody - want to make sure you pay for a license - talk to your sales rep for access  fileconnect.symantec.com)  or if you have the original cd's you should be able to find it.

You don't need FileConnect for this one.  The base client for x64 for 6.0 was released at 6.0 MP2 and can be found here:

Maintenance Pack NB_CLT_60_2_M.winnt.x64.exe provides fixes to the Veritas NetBackup (tm) Enterprise Server / Server 6.0 on Windows 2003 AMD64/EM64T Clients 
 http://support.veritas.com/docs/282644

After you install the client (assuming that succeeds!) I recommend applying MP5 to bring your client in line with your master.  J. already provided THAT link above, but here it is again:

Maintenance Pack NB_60_5_M.winnt.x64.exe provides fixes to the Veritas NetBackup (tm) Enterprise Server / Server 6.0 on Windows XP/2003 X64 server and clients. It also contains fixes for NetBackup Add-on products and Database Agents. 
 http://support.veritas.com/docs/290388

Good luck!

Well...   based on what you guys are telling me; it looks like I have a compatibility issue between my Veritas Server and my Veritas Clients. I saw on the Veritas Support site that I can downgrade my client lisc; but I'm not sure I want to do that. Can I upgrade it without charge later?
Can I upgrade my Master Veritas Server now so that my 6.5 clients can work; and then upgrade all my 6.0 clients at my leisure? Can the Master be newer than the clients?

Who put the bomp in the bomp bah bomp bah bomp?

You can upgrade your server from 6.0 to 6.5 with the correct licenses, these can either be purchased or they are provided to you by Symantec at no charge if you have a service contract in place with them (same for client licenses). 

Yes you can have you master server at a level higher than your clients.  6.0 clients will work with a 6.5 master server. 

Thank you all for your input - I have finally scheduled the upgrade of my master server.

Wish me luck!