I have decided to switch my teams from "boinc uk" to "mindcrack", however, i have found that bam is still registering me as a member of "Boinc uk" on my user page. [here http://boincstats.com/en/stats/-1/user/detail/2604769/overview ]

Does anyone know how i can change the default team that bam registers me as a member of?

BOINCstats sets your combined team by selecting the team you are in on the most projects, if there is a tie it changes between the tied teams on different days.

First if you just changed teams it may take up to two days for the change to propagate from all of the projects back to BOINCstats, just wait.
Second if you changed a while ago check the individual project stats pages here for each of your projects and see which ones still show you are on the wrong team, then go to the projects and fix the problem (repeat wait from 1).

That will be the issue. I keep forgetting that there is a 48 hour wait for most things to do with BOINC.
Thanks for reminding me!