Hello, not sure this is still an issue. If so, do the following.
Go to the My Collection web page by selecting Options > Cloud > Browse My Collection
Select 'My Account' in the top right
Select your account name. (First Option)
Select the link manage your collections
Select Clear to wipe your entire collection
Hope this helps.
P. S. I understand by reading your issue that you understand the steps already. These are mainly for anyone else having this issue who maybe having difficulty.
- Lunchbox (11.7)