Hi Brian,
The warning that you get about the cpu_info device statistic is caused by the fact that with a 9.3.1 LTM platform there is no direct support in the F5 Management Pack for getting the cpu_info device CONFIGURATION from the F5 device. This is a known problem when discovering a 9.3.1 platform and we're looking into addressing this issue in a future release of our F5 Management Pack, either by providing a better user experience (by suppressing the warning in this particular case) or possibly attempting to fix the cpu_info device configuration discovery for LTM v.9.3.1. As you probably noticed, I mentioned CONFIGURATION when failing to retrieve the cpu_info. STATISTICS would still be collected (as you can see in your logs/warnings), but obviously they are useless in your case. This is rather a 9.3.1 platform related inconsistency which has been fixed in newer LTM platform versions.
This being said, you can either disregard the warnings or better, you can completely disable the collection of cpu_info related stats, alltogether, in our F5 Management Pack. You would do this following the step-by-step procedure described in the "Performance Collection and Monitoring" article: http://devcentral.f5.com/wiki/default.aspx/MgmtPack/PerformanceCollectionAndMonitoring.html, in the "Subscribing to Device Statistics: Collection Rules" section. In your case you will look for the CPU info collection rule and creating an override with disabling it. This would make the warning go away.
Let me know if this works for you, at least for the time being, or if you need further assistance.
Thank you,
Julian