can sprint really void warranty/insurance for software

[ryan00davis]

i took my phone in today to get them to fix a couple broken buttons, and they told me i voided the warranty by installing windows mobile 6.1. my claim was that this had nothing to do with the broken buttons, so they should have to replace it, and eventually got a manager who agreed to let me downgrade to 6.0 and he will personally fix/replace it. i've now looked it up and am finding that that's harder than i had anticipated. my question here is how can they void our warranty for this?

i looked up the paperwork and do not see any mention of this, here is a link to the pdf:
http://nextelonline.nextel.com/asset...ure_combo2.pdf

i would understand if we were doing something illegal by putting leaked roms onto our phone, but as far as i know, everything done on this forum is legal.

this is just me venting/wondering how they can do this... here is my link to the more technical side of my problem if any of you have any advice:
http://forum.ppcgeeks.com/showthread...locker&page=14

thanks
-Ryan