I installed LMDE 201204 on my Lenovo ThinkPad T61 the other day (replacing Maya), and when I try to connect to any wireless network, it says it is connected but then flashes "Activation of network connection failed" and then disconnects. Sometimes it will work after I reboot my computer. I do have the correct wireless firmware installed. This issue was not present on normal Linux Mint.
Any insight would be appreciated.