Java – GWT Development mode – Unable to load module in Chrome

I'm trying to load my app in development mode using Chrome v. 20.0 on my local ip 127.0.0.1.
The app fails to load, and the following is displayed:

1. message:
   "GWT Code Server Disconnected
   Most likely, you closed GWT Development Mode. Or, you might have lost network connectivity. To fix this, try restarting GWT Development Mode and REFRESH this page."

2. on top of the previous message (overlaid):
   "Plugin failed to connect to Development Mode server at 127.0.0.1:9997
   Follow the underlying troubleshooting instructions"

This started to happen about 6-9 months ago and after 1 or 2 page refresh, the module loaded correctly. Now, i cannot load my app in dev-mode at all using Chrome. (in firefox
everything is ok).
I'm using GWT 2.4

UPDATE:

Those errors are not accompanied by any code stack trace output. Usually, if I changed the address form 127.0.0.1 to localhost, the module loaded, but this doesn't work any more…