how the job was created? and Whats the name of the job?

Renaming the job should help. can you put profiler and find query which is generating error?

You need to take resource offline from Cluster admin.

Did some one change startup account?

Matt,

My apologies.

I am not sure what "rebuild" mean? Please explain us and let's see if we can help.

I agree with SQLBill, backup would be way to go  

sp_dboption 'autoclose' ,'false'

you need to look at query plan and look for parallelism operator. I am not able to think of an easy way.

What do you expect to see if you have ALTER option available?

I feel that the menu item of Right Click is common for all objects and will be disabled...

Can you please check error log and see if below is applicable?

FIX: Automatic checkpoints on some SQL Server 2000 databases do not run as expected

http://support.microsoft.com/kb/909369/en-us

It looks like Cerificate issues.

Can you please check SQLError Logs and see if there are some errors related to certificate or Encryption?

Steps provided by Michael will work if above is true.

PAE and /3GB are on windows level

AWE is for SQL Server and its the same as SQL 2005.

FIX: Error message when you try to open a file attachment in a message that is generated by the sp_send_dbmail procedure in SQL Server 2005: "This file is not in...

1. Is it on cluster?

2. What is the startup account for SQL and FTS?

3. can you please run below command and send post back

sp_fulltext_service

'update_languages'

In SQL 2005 you need to use "Transfer SQL Server Objects Task" of SSIS. This is having more features as compared to old import export wizard.

hope this helps

Balmukund

i bet database services were not upgraded during upgrade process.

Do you remember seeing "database engine" getting insalled/upgraded during migation?