1. The shares on the other machines might require a user name and password to acess the shares. So they either need to allow anyone to acess those shares through permissions, Or, you need to make sure the user you are logged onto on your XP machine has the same user name and password.... This is just a stab in the dark, I am guessing you are using XP home and not XP professional, Xp home does not have the advanced networking permissions that XP professional does.
2. You may have disable a certain view in I.E. some times installing an update might reset all the setting, but probably not. So try clicking on the view menu on the top bar and see if changiung any of those settings helps you.