AFAIK, IDEALPRO is just like an ECN - totally automatic matching. If the market's crossed, one quote or the other is stale. Did you report it to IB in chat, email, or via trouble ticket?
This whole thing was a glitch. It happened, because two of our liquidity providers started sending us quotes rounded to 1/2 a pip. Our compression software was not expecting it, hence to displaying difficulties. We are hoping to having it fixed for tomorrow. Until the end of the week we intend to display the quotes rounded to 1 pip. Starting next week, we will display 1/2s.
So you're going to have 5 digits (7 for JPY) after the decimal? Do other FX joints offer this? Presumably, this will motivate people to make even tighter markets to get action.
This appears to be worked out ---but be careful. I have found when there is any kind of software glitches to be fixed ---in trading step to the side until all is clear. It does appear to be fine now.