is there something in article 690 that i am missing that would allow 10 awg / 42 amps
Read 690.8, and understand the procedure of sizing conductors for PV System applications. The answer for the inverter output circuits should be #6 Cu.
If the #10 wires are for the DC strings, which is common, these are not "protected" by the 60A overcurrent device that is connected to the inverter output circuit. Also, in this example, there is not 42A present on these conductors (because the inverter converts power format and trades voltage and current from input to output). Instead, these are conductors that would likely either have OCPD inside the inverter, or not require OCPD at all. Because the fault current is limited to only what the module Isc values produce, a single string doesn't require OCPD. And there is also a special exception for two strings in parallel that they can be "bare tapped" together.
For 42A of maximum continuous current (as you'll calculate or select in 690.8(A)), this means you'll need 60A worth of overcurrent protection device. 42A*125% = 52.5A.
For 690.8(B), there are two conditions that need to be met for the wire to be properly sized.
1. The max cont current * 125% must not exceed the ampacity of the termination conditions on both sides of the wire. This is usually the 75C column of 310.15(B)(16), but for 100A and less, you do need to check that terminations are listed and marked for 75C. See 110.14(C) for more detail.
2. The max cont current * 100% must not exceed the ampacity of the conductor at conditions of use. This is usually the 90C column of 310.15(B)(16), and then there are other factors discussed in Article 310 that come in to play. Usually temperature corrections and ampacity adjustments for bundling. These used to be called derate factors, and you will still see this term.
In 2011, there was a third condition. The OCPD where required, shall protect the wire as sized. All parts of Article 240 shall apply for conductor protection. This rule still exists in 2014, and just isn't explicitly stated.