VZW 3G Tether Workaround
After many hours of frustration in attempting to maintain a consistent 3G Hotspot internet connection I think I may have found the problem.
Root cause: The Droid 3G Hotspot is not a dedicated WiFi hotspot like you have at home or in a coffee shop. It is a multifunction device that uses 3G for many other things such as automatically updating e-mail, weather, apps, and other scheduled forms of data delivery. Observation has shown that Hotspot internet connectivity is lost whenever Android uses 3G to perform one, or more, of these functions.
Admittedly, the Droid should not lose internet connectivity whenever it polls for an e-mail update, or checks the weather, or updates a application... but it does.
My work-around consists of two parts; Droid settings and procedures.
Droid settings:
On the Droid, go to Settings/Battery & data manager/Battery mode and set to 'Performance mode'. This insures that there should be fewer 'time-outs' on system functions.
Next, disable auto update for any applications that you can. I.E. I have set Weatherbug to only update once an hour and my e-mail applications to update manually. For ease of maintenance I still use auto update for apps but try to insure there are no outstanding Market updates prior to going online, if they fire off, I will lose internet connectivity. The idea is to minimize the possibility of Android using 3G for something without your knowledge.
Now your 3G Hotspot should not time-out but will require manual update for some applications.
Procedure: The following works for me on Win7 Pro 64bit and my Droid-X.
1) Disable the wireless adapter on the PC. This clears out any previous internet connections.
2) Turn on wireless tether (3G Hotspot) and wait till the 3G and signal strength bars turn from blue to white. I have no idea what this 'mode change' is all about but if the notifications are blue... no internet.
3) Enable the wireless adapter on the PC. Depending on your network settings the 3G Hotspot should connect automatically or you may have to manually connect.
Your 3G Hotspot should now remain connected much longer than it ever did before. However, since we cannot control everything Android does with 3G, we will still lose internet connectivity from time to time. When that happens, reset the 3G internet connection by either rebooting the Droid or using the 'Reset Connection' app from the Marketplace (preferred) and start over with step 1.
Update: It seems that the 'real' root cause of disconnects are OTA updates for applications. This issue is supposedly fixed in the new release version 4.5.621.MB810. I am at 4.5.605.MB810.Verizon.en.US and the update is not yet available.