Some sites use a hidden field to purposefully not remember form fields, you can use a bookmarklet to remove this "protection"...
Make a new bookmark in IE on your bookmark bar, rename it "Save Passwords", enter the fllowing as the address (click yes to protocol error), then when you are at the page for entering your password, click the bookmarklet, It will tell you if it removed any "Autocomplete=off" form fileds... this fixes most normal forms.
Save pass bookmarklet for IE
Step by step:
In IE put "about:blank" in the address bar, hit enter... you'll see... a blank page
drag the icon from next to the adress bar to your links toolbar.
right click the new bookmark and choose properties
change the name to "Save Passwords" or anything you can remember... savepass, whatever
change the address to the above code
test.. goto https://paypal.com/
click the bookmarklet while on paypals site.
Success if it shows it enabled autocomplete on 3 objects.https://login.live.com/
= 2 fields
here is the bookmarklet code for Firefox
for anyone else reading this...
Hope this helps.
P.S. google for bookmarklets, these little things RULE
Also checked https://www.vbulletin.com/forum/
... IE bookmarklet doesnt handle the 1 "onsubmit", but the Firefox bookmarklet I use let me save a password
Maybe you caqn find one that works in IE for those "onsubmit" sites.