It seems my e3000 will drop all wifi connections when 5Ghz is being used and a larger amount of network payload is transferred through the device (eg, http GET large file, ftp, scp, youtube streaming, etc.). I've been through many hours of troubleshooting and experimenting to arrive at this conclusion. At one point in the past I installed dd-wrt, upgraded dd-wrt a couple of times, reinstalled vendor firmware, etc. and so on. I've read about overheating issues with the device but haven't found testimony in which it's noted that 5Ghz is what ultimately causes it to fail. The ambient temperature of the rooms I've been using this range from 40-80F, nothing special.
I am writing to see if anyone is aware of a solution, a statement from the vendor, or anything that might be helpful in my case. Please let me know.
* Also, I discovered just today Linksys Connect Setup Software for Mac is not functional with my operating system OSX 10.10.1. Without use of that software I'm unable to create the 'guest' network. Unfortunately some functionality is not available via the web based interface.