I'm trying your firmware but I'm having an issue..
I didn't compile it though, I'm using the prebuilt binaries on your website (dunno if they are the latest version).
It seems after boot it only accepts one command, like AT... (and returns OK).. after that, any command I give will return ERROR.
When I flashed it the first time, it seemed to remember my AP settings.. and tried to connect.. it gave me this on boot.
+CWSTAT:1
+CWSTAT:5
But then returned error on any AT command.
I then flash a standard firmware (just to see if I was having any flashing issues) and yours again. Now it doesn't show the CWSTAT (probably because it doesn't have an AP saved), but it still gives me error.
This is what I get on bootup with 75000 baud.
ets Jan 8 2013,rst cause:1, boot mode:(3,6)
load 0x40100000, len 23656, room 16
tail 8
chksum 0x3d
load 0x3ffe8000, len 2692, room 0
tail 4
chksum 0x90
load 0x3ffe8a90, len 4452, room 4
tail 0
chksum 0xc2
csum 0xc2