I reported a blatant bug in Modelsim's dealing with libraries. See: http://ionipti.blogspot.com/2010/07/modelsim-working-with-multiple.html.
And it's too bad that they haven't had the foresight to actually fix this problem.
What is nice is that they fixed a bunch of other bugs. There was one that was causing bad results and that had to do with queue slices when sent into tasks within other modules. That is now working correctly.