SOURCEMGMT: Source is invalid due to missing/inaccessible package.

Hi All,

I have built a package and trying to install on a new networked PC.
I'm not sure if this could be to do with group/user policies or not,
but any expert advice would be much appreciated!
The msi is run locally by a user with standard permissions. On a new
PC, the installer should simply unpack a file structure to the user's
PC, to a writable location (verified).

The following part of the log shows the error with verbose logging:

.....
MSI (c) (084) [14:53:43:421]: Machine policy value 'DisableMsi' is 0
MSI (c) (084) [14:53:43:452]: Machine policy value
'AlwaysInstallElevated' is 0
MSI (c) (084) [14:53:43:483]: User policy value
'AlwaysInstallElevated' is 0
MSI (c) (084) [14:53:43:499]: Product {90D754BD-31E6-40FD-A3A2-
D53FB46CD94F} is not managed.
MSI (c) (084) [14:53:43:530]: Running product '{90D754BD-31E6-40FD-
A3A2-D53FB46CD94F}' with user privileges: It's not assigned.
MSI (c) (084) [14:53:43:562]: SOURCEMGMT: Media is enabled for
product.
MSI (c) (084) [14:53:43:577]: SOURCEMGMT: Attempting to use
LastUsedSource from source list.
MSI (c) (084) [14:53:43:608]: SOURCEMGMT: Trying source C:
\DOCUME~1\USER~1\LOCALS~1\Temp\.
MSI (c) (084) [14:53:43:640]: Note: 1: 2203 2: C:
\DOCUME~1\USER~1\LOCALS~1\Temp\GLC16E.tmp 3: -2147287038
MSI (c) (084) [14:53:43:671]: SOURCEMGMT: Source is invalid due to
missing/inaccessible package.
MSI (c) (084) [14:53:43:687]: Note: 1: 1706 2: -2147483647 3:
GLC16E.tmp
.....

The log eventually completes with the following:

MSI (c) (084) [14:54:07:578]: SOURCEMGMT: Failed to resolve source
MSI (c) (084) [14:54:07:625]: MainEngineThread is returning 1612

thanks!
B