SOLVED:
Ok, this one definitely falls into the "user error" category!!!!
So, when I changed my password using my laptop I just typed it into the appropriate text box and again in the "confirmation" box. Signed into messenger via my laptop and my hotmail account via a browser and it just worked. Cool.
Tried exactly the same thing on my mobile and no go. Weird.
So I tried all your suggestions above (barring using POP and Palringo) and still no go. Starting to get annoyed now.
Today I changed my password to something simple and short, to make 100% sure that I am not typing it in incorrectly etc. Try via my laptop & browser, all is sweet. Try from my mobile and it works! Ok getting somewhere now!!
Change my password BACK to what it wanted it to be and once again it broke via the mobile!! Ok this is starting to do my nut now. Anyway, to cut a long story short, when you change your password it tells you that the minimum length is 6 characters but no mention of a maximum, the text box just stops taking characters without letting you know. Same with the confirmation box. MSN Messenger and the Hotmail sign-in page (I assume all Live ID sign-in pages) only take a maximum of 16 characters, so even though I was typing in 19, only the first 16 ever got taken. This being the case all computer/browser based things worked just fine. The Windows Live Mobile client actually takes as many characters as you type in!! So a full 19 character password would never authenticate properly!!
Shortened my password and now it's working!!
So that leaves 3 questions IMO:
1. Why, in this day and age of having to protect our IDs from theft etc, do MS impose a 16 character limit?
2. If they are going to impose this limit, why not tell you somewhere on the page where you can change your password or even automatically warn you when you're typing it in and reach the 16 char limit?
3. If all Live ID based apps and websites only take 16 characters, why is the WLM client different?!
EDIT:
I've updated the title and subtitle of this post so that if anyone has trouble in the future becauseo of this issue they will hopefully be able to find this topic nice and fast.
Edited by Syphon Filter, 22 December 2009 - 01:15 PM.