It kills my connection too!
This means - overnet or any other program which includes internet explorer can not download or upload , the connection goes dead , a reboot is the only cure!
This can occur after 5 minutes or 5 hours but it usually occurs at least 1 time a night when it is running - when i check overnet in the morning the connection is dead!
I have been using overnet for 3-4 months & this has happened since day 1.
No other p2p programs are running & this can happen even after a fresh reboot.
My specs - XPPro 512Mb ram , running cacheman
did it with dialup now does it also with ADSL-256K broadband.
Even with this problem overnet is better than emule for me.
I can download at around 15-24 & can download around 1.5Gb in 24 hours!