WRT610n FTP unstable + Firmware request

Question

A number of things to ask/request for. First off, may I please have an address for Firmware 1.00.00 B18 for WRT610n Version 1 please? Or a link to some kind of program that'll backup my current firmware? I don't like the idea of upgrading it without having a backup of the original that came with the router.
The other thing is, I did a quick check for the same FTP issue as myself and got over 10 pages of results, and a more specific search yielded only 3 which were slightly different issues. I checked the first page of results from the large list and found none of them also applied to my situation so I'm making this thread in the hopes you can help me out ^-^;
My FTP is setup via an External USB NTFS Harddrive. Locally I can access it no problem, but across the internet for some reason access only stays stable for about 12 - 24hrs before complete access failure. When it dies it's a nightmare to get running again, as a simple reboot of the router and harddrive, and even turning off FTP options and turning them back on all tend not to work unless all processes have been repeated at least twice. I'm sure it's probably just one of them or any two combinations that could solve the issue, but having to repeat the process everyday is obviously not ideal. Any ideas as to what the problem is? Since I can still access it locally it's obviously not the enclosure or the harddrive itself, and it shows the router itself isn't hanging up either, so what could be happening that's affecting FTP access via the external server IP itself?

Answer 1

Oh dear, in trying to resolve this problem a new one has been discovered.
At the moment the DHCP server option on the router is turned on. Client lease time is set to default of 0 (1 day), and I suddenly found that none of my machines on the LAN are in the DHCP client list anymore. According to the router, there is no PC or PS3 connected, even though they clearly are, and no IP addresses are assigned to anything, which is odd since I can clearly still access the internet and use it. However I found out that like this, my PS3 can't download anything from the market place, it can only surf and game.
I obviously thought I knew more than I did. I thought the DHCP would assign or re-assign the IP addresses once the lease expired, but that apparently isn't the case. I also thought that if an IP address wasn't assigned or re-assigned after the lease was up, communication from the machine that lost it's IP address would cease to work across the network, but rather than that happening it only appears to be limiting or blocking specific protocals.
It also makes sense that if I can't download from the PS3 marketplace, which uses the FTP protocal, then that'd explain why the FTP server will no longer work via the external IP Address across the Internet. However it's confusing how an IP address that is outside of the DHCP's range, should be affected by the DHCP, and yet the local address which is also outside of it's range, works. (Note: I had Users outside of my network also test the FTP, and whenever I was unable to access it using the external IP, they were also prevented from doing so)
I'm greatly confused by what's going on. Please help me T_T