1.  Try parsing the string together into a variable and then PRINT the variable.  SHOULD help ID the problem

2.  SQL server is aware enough to realize that '2005-09-01 00:00:00.000' regardless...

Pretty much then.  Via linked server I don't believe you can ADD objects however, you can update, delete, insert etc...

Do they use SP's or ADHOC SQL?  I agree with grabbing data with PROFILER.

IF SP then looks for the ones that changed recently and you can look at ESTIMATED execution...

Have you looked up error in BOL?  If you poke around may help...

Error = 0 means EVERYTHING is ok.

have you checked the CLIENT network utility to ensure TCP/IP is enabled there as well?

Have you tried connecting WITHOUT telling it ,1433?  If this is the DEFAULT instance try NOT...

1.  What is the error?

2.  Why are you trying to convert 2005-07-11 00:00:00 to DateTime WHEN you are going to get the exact same information?

Personally I don't know what they are so I cannot tell you if SQL already has something built-in to handle this.

Can you expand on what those functions are?

What permissions did you setup for them to have?  i.e. did you set up impersonate?  or are they using their own credentials///

Sounds like there is bad juju in the stored-proc.  can you post it so it can be eyeballed for possible areas of improvement?

Have you looked at BOL and searched for SELECT INTO....

Start with getting network engineers and server engineers involved to start sniffing network/mem usage

start running profiler to capture what is going on.

Have someone else (other than the original developer(s)) look...

1. Are the servers identical (hardware versions, software, etc. except for SP4) this is to include CPUs, memory, 3rd party software...
2. When the processes run are the other processes similar i.e. no...

What version of SQL are you using?  Which BOL are you using to gather your information?  If you are using 2K5 and the 2K BOL that could be a problem. ...

SELECT *

  FROM Ordhed O1

    LEFT JOIN QCordhed QC ON O1.OrdhedID = QC.OrdhedID

WHERE QC.OrdhedID IS NULL

as an alternative

Try running the below in query pane 1

SET DATEFIRST 1

SELECT DATEPART(WEEKDAY, '2005-11-06')

And this in query pane 2

SELECT DATEPART(WEEKDAY, '2005-11-06')

The DateFirst only affects current execution and does not update...