CASH FLOW question

[Michael Seutin]

I bought 3 ppties so far. I am learning and improving eacth time. But I didn't do so good at first. Here is a recap using the 50% expense rule that I believe in cos it is proven in my ppties.

1st Ppty: SFH bought in 2007, in Austin, Tx,
first year, per month
gross rents: $1000
NOI: $500
Debt Service: $769
Cash Flow: ($269) loss per month

2nd Ppty: SFH bought in 2008, in Austin, Tx
first year, per month
gross rents: $1150
NOI: $575
Debt Service: $708.72
Cash Flow: ($133.72) loss per month
second year
gross rents: $1200
NOI: $600
Debt Service: $708.72
Cash Flow: ($108.72) loss per month

3rd Property: Duplex bought in 2009 in Fort Worth, Tx
gross rents: $1775
NOI: $887
Debt Service: $610
Cash Flow: $277, positive at last

Now the first property I know I should resale but I co-own it and it's complicated at the moment.
My question is the second property, I had a loss of $133 per month the first year and $108 the second year. Now I learned my lesson and won't invest in any more neg cash flow. But should I resale it now? or keep it until the cash flow at least break even and starts to become positive ?
Reselling cost money in fees and rebuying also cost money in fees. And I am guessing that in 2010 I will be maybe cash flow neg $50 and then 2011 will be break even.
What do you guys think of rent increases, what is the average rent increase percentage wise per year ?
Even a slight cash flow negative property might be worth holding at times?
or should any wise investor automatically resale such a property.
When I got started I didn't have the same knowledge as today but I told myself that as Warren Buffett did, I would only buy but never resale.
Opinions please.