Iphone 3G New OS question, Please Help

[povsicf]

I have an iphone 3G, and I paid Developer to add my UDID to his account, and got the new beta 3.0 1,2,3 but when I went to upgrade to the 4 with the pre release of 8.2 itunes, I kept getting error code 6, 3/4 of the way through. I tried pretty much everything. So I decided to find a PC and downgrade back to 2.2.1 Everything works just fine now and I have no problems, my question is when the new beta 5 comes out, would I be ok to try to upgrade to that? If it doesn't work, will I be ok downgrading back down? Most importantly though if it doesn't work and I downgrade back down to 2.2.1, or if it does and I can upgrade to beta 5 and the rest of the betas, will I have a problem when the official release comes out in upgrading to the final release, or will I be ok???? Thanks in advance for all your help in this.