No, the problem is not isolated to SG300-28Ps. My issue was orginally with a SG500-52P. The tech I spoke with said the MP (max power) switches are wired differently from the regular P switches. Since your not having issues with the SG300-10P or 28...
For those intersted in sticking with Cisco, I swapped the SG500-52P for an SG300-52MP and it seems to resolve the issues. I put four Ruckus ZoneFlex 7982 APs in adjuacent ports (7, 8, 9, 10) and the all powered up.
I have the same issue as the original poster with my SG500-52P and Ruckus ZoneFlex 7982 APs and HP NJ2000G IntelliJacks. I just spent about an hour on the phone with support. After running through a bunch of tests, with the tech watching the switch...