The site uses cookies to identify you; so if you dumped yours recently, it wouldn't have logged you in, it's easy to not notice that. Also, sometimes it just happens; I've had it not log me in one time, and do it the next, with no change I was aware of...
Cables - midi will start to lose bits through pulse rounding somewhere around 8 meters, depending on the sender and receiver modules and cable capacitance; generally cheaper midi cables are more likely to have higher cable capacitance and will start dropping bits

at shorter lengths. For the lengths you want, you'll probably have to get some midi through boxes to insert along the way;
commercial midi cables come in up to 20 foot (6.5 meter) lengths; I have a couple of those, and haven't seen any dropped bits. However, I've NOT done any tests to see how much TIMING error they generate, I've just tried to keep them on slower stuff, like string pads and NOT drums, just in case.
Firewire - 4.5 meters is considered max without a repeater (hub) but these guys have other options -
http://www.unibrain.com/1394_products/cables/cables.htm
More, including pinouts for firewire -
http://www.pccables.com/cables/firewire_cables.html
USB -
http://www.motu.com/techsupport/technot ... 74677/view
http://www.vpi.us/usbc5.html
Basically, you will need to use some kind of extender boxes to get the distances you need; probably the cleanest way to do this is with Cat5 cable, it seems most stuff can be extended this way now (including 16 channels of 16/44 digital audio on one Cat5 - google the words QSC and RAVE for more on this.
Jack plates - good quality ones won't hurt NEARLY as much as stepping on a cable that runs clear back to your mix position with no breaks, and having to either shorten the cable or

pull a new one;
For syncing video and digital audio WELL, you may want to budget for one of these
http://www.nanosyncs.com/nanosyncs.html
Around $1400 is best street price. This can lock to video and output locked audio word clock, etc - check the link for more... Steve