It's not related to the bitness. It's the MAC address resolution order.
It's happening because for any IP address outside of your subnet, the router responds with its own MAC address rather than target node's MAC address.
You just need to change the following settings to fix it: go to Options - Settings - Additional - Resolve MAC address. Reorder the entires as:
- Router MIB query
- NetBios query
- ARP query
Hope this helps.