While the press has been talking about the problems with the Samsung Galaxy S4 talking to the DIR-655 and DIR-855, I have the following:
Model: DIR-615
P/N: BIR615ANA.....B2
H/W Version: B2
Firmware Version 2.20
The Galaxy S4 phones are from two providers; one is on Sprint, the other is a friend who uses AT&T or Verizon. Both drop the wifi in under a 15 seconds.
The DLink H/W rev B last firmware update: June, 2008, to version 2.25 (Well before the Galaxy S4).
There is a beta update on March, 2011 that's "at your own risk"
I'm going to try the version 2.25 to see if it works.
The hardware rev C and E were both updated about 6 weeks ago. Any chance the Rev B will be updated to fix the compatibility issue? The web page for the DD-615 says it's still a "live" product.
http://www.dlink.com/us/en/support/product/dir-615-wireless-n-300-router (<==link)
Will post results in a few days; I mostly wanted to document that this is occurring on the older routers as well.