The DNS for IP ranges 157.55 and 157.56 have been updated. He said:
I've been keeping a desultory eye on the MS 157 ranges for some time. Not sure when it actually happened - probably within the past few weeks - but MS seem to have taken notice of complaints - or just finally got their act together.
I had a handful of IPs tagged as msnbot in my database from a previous DNS scan some time back. The new ranges/sub-ranges (about 100) extend this range but also, in some cases, extend or reduce previously logged ranges. The list I now have, taken from DNS scans of the MS DNS servers, is included below. I think the list is accurate but I cannot guarantee it.
If you are using any software that detects IPs, you may want to check out the thread.
Forum discussion at WebmasterWorld.