Only two or three reports of wifi issues out of over 1000 downloads, seems to be either an issue with your particular router (possible) or you need to do a full wipe/format and reflash the ROM.
Note-when I say reflash the ROM, I mean re-download it and flash the new download, checking the posted md5 checksum
Note2-when I say full wipe/format, I mean wipe cache and dalvik cache, then format boot, system, cache, and data. (this of course means a full reinstall of all apps, so backup first)
If you are having wifi issues, please let us know which build you are using, and what type of router you are using.