After a wi-fi upgrade to FW 4.5.9587 my Glo(non HD) is not connecting to computer through USB. I can not read/write any file on it. It is rendered practically non-modifiable. Various attempts to connect it through different cables/computers have failed. Only charging the battery is possible. The device is working normally otherwise. Restarting the device many times also does not solve the issue. Did anyone else experience this connectivity problem?
I want to revert back to my earlier FW 3.19.5761, where my life was not that miserable. Please suggest me how can I go back or solve the connectivity issue?

After a full day of chagrin I'm feeling a hopeless sense that the situation is so bad as to be impossible to deal with at my level. Please help!!

I'll be highly thankful.