Problems with old live account

Dear community,

I am having difficulties logging in to my office 365 P1 account and my (old) live.com account.

I performed these steps to complete my office 365 account:

1. I used to have a microsoft account (former live.com account) registered at my address myname@myowndomain.nl using my default password.
2. I created my office 365 account and registered it using myowndomain.nl.
3. I have modified domain registration, and registered myowndomain.nl with office 365.
4. This resulted in myname@myowndomain.nl as an office 365 account (as well as I have myname@myowndomain.nl as a microsoft live account

I expected microsoft account to 'link' these 2 accounts and make it one as they both have the same username and password combination, so there is no way to determine whether i am logging in to office 365 or live.com.

However, now I am facing various errors like 'this account cannot be used using outlook.com', or an aspx errors when trying to open my team site 'home' or 'admin' page on the office 365 portal.

Please guide me on how to fix this sign-on issues as either my new office, or my old live account cannot be used without experiencing problems.

Please note that I DO need to keep the live account, as it is used for my Windows 8 authentication and the messenger application. 

Thank you!