Is it normal for Online Checkin not to work ?

I am flying out of T3 tomorrow on a BA codeshare flight with Iberia to Madrid.

Last trip I could n't use the online check in.

This morning I get an email from BA saying Online check in is now open.
I try and it says I can't.

I go to the Iberia flight which says clearly that codeshared flights in my number range cannot be checked in online.

Is this normal for Codeshare flights with BA ?

Mark

Do you know the availability on the flight?