Default [Q][solved] wlan problem on Mini Pro

Hello and Sorry my bad english

But I got wlan problem whit my rooted and cyonogen mod 9 installed mini pro

I cant download over wlan connection big apps from f-droid or straight from the internet. I have managed download Irssi and AdAway apps put i cant download firefox(or any other browser) on my phone on wlan connection because downloads allways stop on about 20%. The wlan usually works 2min on web suffing and then it stop working.
I have to reboot my phone or turn of the wifi and then turn it back on, but it will work only 2min again.
I have installed the cyanogen mod again but that didnt help me. My phone worked fine a month before this problem start.
I have sooner some wlan dropping problem put i managed fix that problem by removing this file /data/misc/dhcp/dhcpcd-wlan0.lease

I am very happy if someone can help me because i have very slow mobile internet.

Sorry my bad english.