Thank goodness for archived discussions!
I've been having the "Server Connection Interrupted" error from my Time Capsule for some time, and was pulling my hair out when I accidentally found this discussion by doing a Google search (using Apple's discussion search engine didn't pull up ANYTHING related to this for me).
1. It seems that most if not all of the people having this problem also have an external hard drive connected to their Time Capsule. This problem started for me after I plugged a Western Digital 1TB non-powered external hard drive into the USB port of my Time Capsule to store/manage 200GB of iTunes music files.
NOTE: I had not read Apple Information Article HT2421 about Airport products that warns users NOT to plug any non-powered hard drives directly into the USB port on a Time Capsule:
2. Even after disconnecting the non-powered external HD from my Time Capsule, the disconnect errors continued. The suggestion found in this thread of switching from Time Capsule Firmware 7.6.1 back to 7.5.2 is what ultimately fixed the problem for me.
3. Final Solution: WD non-powered hard drive is now connected to an AC-powered USB hub, which is then plugged into the USB port on the Time Capsule.
I have had a Time Capsule for 4 days and got this message from the very beginning.
I have it set up in bridge mode, as I've tried multiple routers (including an Airport Extreme) and I've found that internet performance suffers when you use anything but the ISP's provided router.
I am receiving the very same server connection interrupted message, and just got off the phone with an AppleCare Advisor who told me that this message is expected and normal when it is in bridge mode, and that ultimately there is nothing that can be done to get rid of the error, unless I put the Time Capsule as the primary router on my network.
This is ridiculous, but I guess I will have to return it.
I have Airport Extreme (5th Generation) connected via a NetComm Gateway Series ADSL2+ 4-Port Modem Router (Model NB6Plus4) setup in bridge mode (no WiFi in this box).
Airport Extreme handles PPPoE Internet connection, and all router functions (DHCP, NAT, WiFi, etc).
And it works just fine.
There is no loss of performance. I am about 2.5 km from the Subiaco WA Telstra exchange building, and see 10Mb/s flat lined maximum, as expected, at that distance.
(I subsribe to a 20Mb/s service, thruput is attenuated by the distance).
There is no technical reason your should see poorer performance from your Time Capsule.
a) Set up your ISP router in Bridge Mode, (direct connect your Mac via Ethernet to set it up, but you probably know this already)....
b) Set up your Airport Extreme as your Base Station, configure the Interent Connection, Wireless, and DHCP host.
c) Setup your Time Capsule to extend your WiFi network, or better still, if is close to your Mac, connect via 1Gb/s Ethernet. This wil get you the optimum performance from your setup.
I recently bought the NetComm NB6Plus4 after my LinkSys WAG160N died.
NetComm is an Australian Company, and I am very happy with performance and price (AU$90.00).
You certainly do not need to persist with the Router provided by your ISP.