It does not sound like a tcp/ip issue to me but a software bug. Since it's closed source we have to wait for brother to supply a fix.
I have a brother dcp540cn multifunction centre connected by ethernet cable to my network. It works fine with all 3 windows xp machines. I recently purchased an Acer Aspire 7552G-6851 with Windows 7 home premium x64. I downloaded the Windows 7 x64 software from the Brother website and installed the suite successfully. It even showed the scanner on the network for me to chose to connect to. Unfortunately when I attempt to scan in Control Centre I get the following message:
Failed to connect to the device.
-If the device is OFF, turn ON the device.
-Check the I/F cable connection between the device and your computer.
-If the device is working with another job, wait until the job finishes and try again.
Then when I click OK it displays the following error:
Please try to scan the image again, if the error happens again please restart your computer, and then try to scan again.
Of course this does not help as none of the above issues is the case. The status (ink level) monitor originally showed the device as being offline but now works and shows printer online and displays accurate ink levels. Printing to the device works fine, however, I had to search for network printers to connect to it the first time. Furthermore BRAdmin pro 3 has no problem finding the device on the network and also tells me my ink levels.
I have tried using both wired and wireless network connections, neither made a difference.
I have also tried turning off the firewall, this does not help
I suspect this may be an issue in the tcp/ip setup but I am not sure where to start, especially with Windows 7