I also had lock-ups with mine.
03:00.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8111/8168B PCI Express Gigabit Ethernet controller (rev 03)
I tried with Ubuntu 11.04 and Fedora 15.
After 2-5GB had been transfered the system locked up. In Fedora it also did reboot.
This happend when copying via SMB or SFTP (on both sytems).
After installing the realtek-driver from the homepage everything worked fine again.
Just copied 50GB via SFTP without a problem.
I also had lock-ups with mine.
03:00.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8111/8168B PCI Express Gigabit Ethernet controller (rev 03)
I tried with Ubuntu 11.04 and Fedora 15.
After 2-5GB had been transfered the system locked up. In Fedora it also did reboot.
This happend when copying via SMB or SFTP (on both sytems).
After installing the realtek-driver from the homepage everything worked fine again.
Just copied 50GB via SFTP without a problem.