I'm going to guess that Minera and Gridseed get along just fine. I do know that some pools don't work well with Gridseeds. So, in your case, it is likely as you say - a pool issue.
I, however, am not using Gridseeds. I have something substantially bigger. I am reasonably confident (from troubleshooting things with 30 years experience in Unix, Dos, and Windows) that the USB driver is not compatible with the ASICs I own. I could never get Minera on the R Pi to work with any coin on any of the 30+ pools I use. Always HW errors greater than 95%.
I suggest to the person who originally posted a problem mining SYS through Minera with a Zeus based ASIC (that includes GAW) - use something besides Minera. Since you don't own Gridseed, don't rely on Gridseed troubleshooting measures. You do own Zeus manufactured hardware, and so did I at the time of all the trouble.
I tried it and had the same experience. Minera doesn't work very well for me at all, ever. Regardless of version and any tweaks and regardless of what miner software I activate within Minera, it's low rate and higher than 95% HW errors.
I did discover that an Atom 450 based netbook running cgminerdmaxl with USB hubs can easily handle 10 ASICs, if that helps you any. I ran that way for a week, to see how it would go.
A quad AMD Phenom with the same setup does just fine and can handle even more ASICs.
Is anyone mining SYS using Minera? I have been having a real hard time finding a pool that is compatible with the mining software (and doesn't screw you on the hashrate).
I found it has more to do with the pool. The blades really run well under minera. Just have to connect to the right pool. I tried MinderPools and the offical pool, the miners doesn't like either. The pool was under reporting the hash rate by 10-15%