For all our service-based applications, the 'engine' of the product runs as a Windows service. This service therefore needs to have access to your LAN folder. By default the service runs under the 'SYSTEM' account which has *no* access to LAN folders.
You have to go into the Options -> General tab and click on 'Service Settings' and change it to run under an account that has *default* access to the shares.
By 'default' I mean that, if the username/password to access shares is different to the username/password for that local account, it will only work if you check the 'Reconnect on logon' option when mapping the network drive (or browsing the network neighbourhood). A simpler method is to make sure the local / network account details match. Or the LAN folder can have no authentication at all.
Note that once you do this then you cannot run IVM as a service anymore because it no longer runs under the 'SYSTEM' account. But this is a Windows limitation, it is simply not possible to access network shares using the SYSTEM account and without logging in to the computer.