From my recent observation through speaking to a few people who have been doing for ex. desktop types of support for anywhere from 1 to 3 years, it seems as though they have a complaint that they're stuck doing it and it's hard to break into another level.
Did you go from a tech support person and got enough experience and then got promoted to a sys. admin with your same company,
OR did you leave for an admin position that you got an interview for. (if this is the case i assume you at some point got to do a mix of sys. admin and desktop support stuff before you left).
Those that complain about this say that those in the sys. admin department try to keep seperate from the desktop team for job security etc., if they have an opening they'd hire from outside, one who is already an admin rather than taking the most sr. desktop guy to train him into the position.
so what's your story of how did you crack into the Admin level?