Yes, we're having a similar problem.
This is our case:
- RUT240 with firmware version 1.41.3
- We´re querying an equipment that's in our LAN every 15 seconds.
- To reduce power consumption, this equipment goes up only for 30 seconds every 15 minutes, so most of the RUT240 querys aren't answered.
- We've noticed that after 3 or 4 hours, the RUT240 stops querying.