From Qik:
The problem with the N95 is that the US version can't switch between 3G and GSM without crashing the phone if there is a load on the DSP (like there is when Qik is running), even if Qik is using WiFi.
The solution is to lock it into 3G mode (which should be fine anywhere in AT&T's 3G coverage cities). In rural areas it can be locked into GSM instead.
Go into tools -> settings -> phone -> network -> network mode -- set to "UMTS" (not "dual mode"). This locks it into 3G mode and prevents it from crashing while streaming when the phone gets the bright idea to switch networks (which it should not be doing so much to begin with). You can also lock it into GSM mode if you're someplace outside AT&T's 3G map.