Unable To Load Package

I have created an SSIS package in BI dev studio which i can debug and run fine. I have saved the dtsx file to a production server which calls it using dtexec as part of a batch script (we are migrating from foxpro). I am getting the following error that i dont understand.

I dont know if this is relevant but i cant execute packages by double clicking them as DTexecui is not installed (not sure why as i have installed the client tools and integration server). Hardware is Dell poweredge 2850 dual xeon 2gb ram with win 2k sp4 and sql 2005 sp1.

Microsoft (R) SQL Server Execute Package Utility
Version 9.00.1399.06 for 32-bit
Copyright (C) Microsoft Corp 1984-2005. All rights reserved.

Started: 12:29:19
Error: 2006-07-06 12:29:20.75
Code: 0xC0011007
Source: {B06EB426-BBE8-4E09-87FC-32ED753A142F}
Description: Unable to load the package as XML because of package does not ha
ve a valid XML format. A specific XML parser error will be posted.
End Error
Error: 2006-07-06 12:29:20.79
Code: 0xC0011002
Source: {B06EB426-BBE8-4E09-87FC-32ED753A142F}
Description: Failed to open package file "\SERVER_AScriptsCLIENTPackage.dtsx" due to error 0x800C0006 "The system cannot locate the object specified.". This happens when loading a package and the file cannot be opened or loaded correctly into the XML document. This can be the result of either providing an incorrect file name was specified when calling LoadPackage or the XML file was specified and has an incorrect format.
End Error
Could not load package "\\SERVER_AScriptsCLIENTPackage.dtsx" because of error 0xC0011002.
Description: Failed to open package file \SERVER_AScriptsCLIENTPackage.dtsx" due to error 0x800C0006 "The system cannot locate the object specified.". This hap
pens when loading a package and the file cannot be opened or loaded correctly in
to the XML document. This can be the result of either providing an incorrect fil
e name was specified when calling LoadPackage or the XML file was specified and
has an incorrect format.
Source: {B06EB426-BBE8-4E09-87FC-32ED753A142F}
Started: 12:29:19
Finished: 12:29:20
Elapsed: 1.719 seconds