Yes, this has been mentioned in various other threads already. Unfortunately, it seems to be an iPad issue in general, as the 1st Gen iPad had the same problem. For some people anyway.
Yes this issue does exist. Seems to be better for some on 4.3.1. I havent noticed any wifi bugs on my first gen iPad on OS 4.3.1 but enought have complained about it. It may depend on your internet provider, router, or if a WPA or WEP settings for the severity of the wifi problem.