Hi CHL - I agree with blocking IM's, especially at work. I think we still get one side of the story without you here - and it's easy to have sympathy for that one side when we don't see the rest.
Of course, a lot of us have BEEN where she is. It took me months and months to get through it. She often seems to take it personally that you are not able to talk while at work, sorry about that.
I would probably just cut off the IM's. It doesn't seem to help either of you. I couldn't even get through them all, it just was too much. I can see where I screwed up and if that happened to me (with someone else) that I'd go bonkers too. I don't think men overall are that bad, we women are the ones who often will just talk and talk until we figure things out.