Many people ( including me) always were unsatisfied with the way 3ds Max handles viewport switching. Even more people got upset after the general viewport switching logic completely changed with ( as far i remember ) Max 2010. Many even suspected a bug in the new Max release, as lots of threads on The Area and elsewhere show.

Just check the following links ( or google for “3ds max viewport switching” )

• The Area: do you like…
• The Area: viewport switching take 2
• The Area: no “memory” of ortho views
• The Area: viewport switch bug

There are other scripts around already, which restore the pre Max 2010 viewport switching, but this script goes further:
It keeps a memory for EVERY viewport type you used in a Max session, more than the previously possible maximium of  4 viewport types. This means you can switch from and to any viewport as much as you like. You will not loose your objects focus in the viewport any longer, if you decide to switch to a viewport you havent used previously.

page: http://www.frogsinspace.at/?page_id=500