Make sure you're close enough to the access point to stay connected indefinitely. Also, make sure cordless phones, steel cabinets, etc aren't interfering with the signal.
Give us the detail on these errors.
I had the same problem, drove me mad.
Fixed it by uininstalling in control panel and then a reboot.
No issues since. I have reinstalled vista 64 a few time (mb Issues) an its never reoccured.
buy a new one?