Can we be evicted after we had a payback agreement? (WA) (tenants, evict)

[Taylorslanding3]

We moved into a rental July 2011, I was laid off from my job 8 weeks later. I had some Unemployment, but was not able to get a new job right away and we could not pay rent. The property owners live back east and their daughter and her husband live here on the property as well, but is being run by a Property Management (Gilpin Reality. I told the daughter about our situation and she said that we were the best tenants and would speak to her mom about our situation. They reduced our rent from $1,295.00 down to 765.00 for that month (which we believe is their mortgage payment on this house). I did get another job, but was laid off from that job within a few months and we only had my husbands income and he has child support taken from that. Therefore, it is very hard to live on $1500.00 a month! Any way our rent continued to get behind further and further. They served us with a 3-day pay or vacate, we worked out a written budget to pay them back for the past due rent and current rent, and I have it in writing that Gilpin Reality agreed to it. I gave them a bunch of post-dated checks, which they have been cashing. Then we received another 3-day pay or vacate last week again and now they are saying we "have" to move? Can the property management company do this to us when the Property Management agreed to the pay back of the rent and they have been cashing the checks? We have been looking to move, but finding it hard to find a place, as there is not much out there. In addition, we plan to move as soon as we can, but as I explained to them, we now have to save to get a 1st months rent and last months and damage deposit, and if we had that kind of money, we would not be behind in rent and be current with them (duh). We were served with this second 3-day pay or vacate on 3/14/12. Don’t we have the legal right to stay here because they accepted the budget in writing to us and cashing the postdated checks I gave them to pay back the rent? Oh, I am back to work full time as an Accounting & HR Manager and we are both making good money now, which we told them, but they do not care. We have had no problems here except the roads to get back to this place is pure mud and pot holes all over the place and because we were trying to pay them back rent, we could not afford 2 new tires on the back of our mini van, and to get up the hill we almost spun out from the tires (which they were replaced the following weekend and I have proof of that) and that is when the owners son in law came running out and yelling at my husband and we tried to explain to him because the road was in such poor condition and our tires being bald, that he had to step on it to get up the hill. He continued to yell at my husband and then all the sudden we get the 3 day pay or vacate a week later. Just all very strange as they have told us repeatedly what great tenants we are, how well we keep up the property and they did not want to loose us. Can they still evict us... have never had this happen before, so not sure what to do.