Issues syncing apps between itunes and ios devices - changed itunes store

I have had an iTunes store account for several years with the same apple ID. Initially I connected that apple ID to the Belgian store and about 2 years ago I changed to the UK store, but still with the same apple ID.

Since I have several IOS devices, I prefer to use iTunes to update any apps I have downloaded and then sync them onto all my IOS devices using my local network rather than downloading accross the internet each time. When I view the apps in my library it says a number of updates are available (right now there are 9). but when I click on the button to go to the store and retrieve the updates - itunes store says "No Updates are currently avaialable" and suggests I sign in with a different ID. However, I don't have a different ID.

This seems to be that any of the apps I puurchased in the Belgian store prior to switch to the UK will not update. For a while, as a resolution, I was able to download updates on one or more of my IOS devices sucesfully whicever store I purchased them from and then when I synced back to iTunes, it updated them in the library. Wasn't very pretty but it worked.

Now after upgrading to iTunes 11, although I can still update the apps on my IOS devices, when I sync it no longer transfers the updates to the iTunes library - I haven't had iTunes 11 long enough to determine if it's related to the same store switch issue or if it's a general problem.

Anybody got any similar experiences or solutions to consolidate all my purchased apps (which ever store) into one, so updating is transparenet again?