It would appear that Nokia has found the fix for the 3G connectivity issues that plagued the North American debut of the Nokia 5800 XpressMusic and that forced the company to halt sales just days after the launch. The issue appeared to plague users in New York and Chicago specifically.
Nokia has come up with a new ROM firmware which will be applied to the available stock. It will also be pushed out to customers who held on to their 5800 XpressMusic phones. To check to see if the firmware is available to you, open the dialer and type in *#0000#. This will bring up the device manager from which you can select ‘Check for updates’ to see if Nokia has released the update yet.
Nokia has not provided any details as to when the Nokia 5800 XpressMusic will go back on sale in North America but it should not too long.
Source: The Boy Genius Report