NAS rebooting modem problem?

[Demon Cleaner]

I have the strange feeling that my new NAS (LaCie 2big network 2) is doing something to my internet connection.

Yesterday I noticed whilst copying stuff onto it, that sometimes Windows showed me the message again "new ethernet disk found", and during that time the NAS was stopped.

Tonight when I was sitting at the PC, NAS was running, although in sleep mode, my internet connection went away like 3 times in 10 minutes, the modem was just rebooting. The NAS is connected directly to an ethernet port on the modem itself.

I powered now the NAS off, and now the connection is staying.

EDIT: I think that was a wrong alarm, it worked now for 20 minutes, NAS was off, but it rebooted again. I also unplugged now the cable. Perhaps the modem is too hot, or the ISP has some problems.