I've not had any WiFi issues using .214 or .225 - but the BlueTooth is a b***h. The only service I can get is the DialUp Networking service... but thats a different topic's - sorry!
I guess that I do not understand why switching to wifi, when available, would be a problem. For example, right now my 9800 shows the wifi connection and EDGE on the top banner. I just took a call and that worked fine. Just before that I received an email from my personal email account. Since starting this message I received an email from the BES. One app that I know uses BIS-B for Transport is Berryweather. It is set to update at 30 minute intervals and that works whether I am in an area with a wifi connection or not. So, I cannot tell that there is any loss as a result of the device using wifi instead of BIS if that indeed happens.