randomly disconnecting and resetting the NIC

[shades_aus]

I am runing a Windows 7 x64 host OS with 16 GB ram and trying to run a Windows 7 x64 Guest OS under VirtualBox Beta 2
I get Random disconnects and re-connects of the Network card. There is no Windows "bong" heard when this happens however, any VPN conncetions or network transfers are terminated.
This seems to have happened ever since 4.3.24-98716 and is worse using a XP Guest Os. Same with Linux hosts.

Network is NAT\Intel PRO.1000 MT Desktop (82540EM)
Changed to PCnet-FAST III - no difference.

[shades_aus]

I'd just like to add on to this.
Issue is still occurring on Windows Server 2012 x64 32 GB ram as a host OS running windows 7 x64 guest.

I have now downgraded to 4.3.20 and everything is once again fine.
I still cant use my host modem inside my VM guest OS and make a PPP connection, that has been broken for a long time also.

[vushakov]

Please, provide VBox.log file.

On Windows hosts this sounds like bug 13839. Please can you give testbuild a try as per comment 42.

However "Same with Linux hosts" doesn't fit that pattern. Again, please, provide a VBox.log.

[shades_aus]

Although the disconnect/reconnect seems to be faster and not always interrupt transmission, it is still an issue. ESP for VPN traffic.
I now notice a flickering of the connection for the NIC very quickly, like a LED would flicker. Sometimes a window pops up in windows saying disconnected, sometimes it's too fast.

My log file is attached.
VirtualBox-4.3.27-99378-Win.exe

This issue is actually worse on the BETA version.

It may be worth noting that 4.3.20 seems to be stable.

Also, I have had to use the 4.3.26 Extension pack as the link in the "test builds" is broken and Google searches have lead back to Oracle web sites that FireFox reports as having corrupted data and page not found issues.