Sandor, sorry to keep following up on this. If you don't fave time to investigate, is there a way to obtain the source code of 0.9F version so I can compare it to the latest one? Something must have changed and I can try to figure it out myself.
Works fine here.

Thanks for the response. Does it work for you when connecting to us-east01.miningrigrentals.com:3333? I don't know where the other port is coming from, it seems like they redirecting my connection.
It works fine on 0.9F
cpuminer-gc3355 (v0.9f) - Started: [2014-05-12 23:00:49]
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(2s) | 3.39/3.64 MH/s | A: 1143 R: 3 HW: 41
Connected to us-east01.miningrigrentals.com:3333 diff 512 with stratum as user toxic0n.749