ubuntu cannot remember a password for automatic reconnection

We bought a new Acer laptop with Windows 7 as the OS. We loaded Ubuntu 11.10 in addition to that. We use Ubuntu exclusively and kept Windows as a backup and to accommodate hardware that Ubuntu has problems with. Ubuntu has never had problems accepting Printers but has had problems with some Scanners and Cameras. Windows has readily accepted everything that we have thrown at it.
We have an Internet Stick plugged into a WiFi dock for our Internet access. The service is provided by Wind Mobile the worst Internet / Cellphone service in Canada. When we first connected with Ubuntu we were asked if we wanted Ubuntu to remember the Password. We said Yes. For a long time after that whenever we connected Ubuntu remembered the Password and automatically connected us without our having to do anything further.
Unfortunately the Wind Mobile connection regularly drops out necessitating that we regularly reboot the Internet Stick. For some reason Ubuntu no longer remembers the Password requiring us to reload the Password at each reboot. Windows on the other hand continues to remember the Password reconnecting us automatically. How can we get Ubuntu to again remember the Password for an automatic reconnection?

Question 2
Turning on our laptop we are given the choice of using Windows 7 or Ubuntu. Windows 7 is the default system. Is there some way that we can make Ubuntu the default system?

Question 3
We use LibreOffice Writer as our word processing software. It has a feature that we do not use and do not like. Drafting a document it will complete words that we have started writing as suggestions for completed words. We hope that we have explained this feature adequately. In any case how would we go about turning off this feature?

We are old and really poor at this sort of thing. We would appreciate it very much if you could explain the solutions to our problems like we are not too bright four year olds. We promise not to be offended.