RB450G freezes on no-use

Everything was working fine on v3.27.
Since upgrading to v4.0 my RB450G freezes when there is no data received/transmitted through the router for a while (have not found if this is on a regular basis, i.e., if router is not used for X minutes).
(RB is used at a school.)

During the daytime, everything is working fine.
In the evening I notice that my website can’t be reached from home or any other non-local location, ping is not working and it is not possible to login to winbox/telnet/putty.
I need to wait for several (5-~15) seconds to get a respond (the website opens after a refresh + ping is back + it is possible to login to RB) .

Tried upgrading to v4.1, then v4.2, then v.4.4 - no changes.

Any clues or ideas?
Any more information needed for a possible solution ?

Made a downgrade to 3.30 and the problem solved.

Upgrade back to v4.5, update the bootloader, and then make a supout.rif file after one of these freezes. We haven’t seen anything like this, so it would be interesting to see those files.

the supout.rif is available here: http://png.edu.lv/mt/supout.rif

the file shows only a manual reboot some time ago, and no crashes recently

Thanks for checking the supout file!

Well, it’s not like crashes with a reboot. It “just” gets unavailable from the outside (with ping message “Destionation host unreachable”) for those 5-15 seconds.
Will try looking harder through some settings and checking the local network - maybe there are some local IP conflicts causing the situation.

My RB450 (4.5) is also have some strange freeze … let say every few day cpu is going to 100 % … and Im find (think so) that is something bad with my adsl line …
Just before one hour traffic is stop and cpu go high … in that moment I was near and just enable and disable adsl interface … and everything is back to normal , but sometimes RB450 reboot (if I wasn not there) after some time and I only see in log :reboot by watchdog …
Look to me like same problem … but Im think that is caused by my bad adsl line.
Is there some tools which can show what proces cause high CPU? like task manager in windows