It sounds like an IP addressing issue, and hopefully it is something simple like that.
Can you try holding the Reset button for 4 seconds (that or 10, I don’t remember). It will not harm your data. The Reset only removes the Admin password from the UI and resets the Network Configs to default.
While the drive is booting up reboot your computer as well. To refresh everything.
If your network configuration was changed, this should fix it.
If it does not fix the problem, can you provide some more information?:
Can you discribe how you have it connected? Is the drive directly connected to your computer, or are both connected to a router/switch?
What version of Windows are you using?
When the drive was connected to the other network, were any setup changes required?
Is the light on the drive Green or another color?
