Child Support between Oregon and Guam

I have a few questions. My husband has a child residing on Guam. There was a temporary support order issued, however he lost his job and we moved here to OR. She has now found out that we are here and has again picked up with the case. She and the child still reside on Guam, and the case is being brought up from there.
Here are the questions?? Firstly, he didn't have a job for several months, and then worked for a short period, and since then has had no income. (He just started working again a few weeks ago.) However I worked during that time. We have a joint account including savings, and checking. All of the money in the acct, has been through my employment. If there is an amount in a sum able to cover the past due child support will that be considered/garnished, even if it is a joint acct.?
If a wage assesment is done for the case would it be according to Guam or Oregon standards?
Also, we have one joint child and one non-joint child. I do not have a job & the non-joint child has papers legally showing that my husband is his guardian...Would that affect the assesment they do on wages?
He does not want anything to do with his child other than paying the support ordered. Can she in anyway establish visitation without his consent? And then there is the question of when he pays the child support can we then claim that child on our taxes?
Finally, she is claiming that he never supported the child since he was born however all medical coverage was provided by him. And they remained a couple until a year and a half ago. Is there anyway we can prove that in court so that we do not have to pay back child support to the day he was born?

If you want to modify support for any reason, you should petition to have support modified. If you choose not to do so, you're usually stuck with the consequence even if you would have qualified to have support lowered had you acted sooner. Further, it is unlikely that the Oregon court could modify the Guam support order. If there are ongoing support issues or claims, he should consider hiring a lawyer to assist him with resolving those issues. Garnishment can occur from joint accounts, as the money in the account is ordinarily considered to be a joint asset (both parties having equal rights to the full balance).