can anyone (kenshirothefist: *poke*) summarize the problem with cgminer 3.7.2 and NiceHash's scrypt pool, point out the breaking commit (between cgminer 3.1.1 and 3.7.2) or the fix (in sgminer) relating to it?
btw, great job on this service so far! it's great to see some innovative new pool ideas this year

cgminer 3.7.2 has many many bugs that have since been patched in newer versions and branches such as sgminer. There's really no good reason to be using an old version of cgminer anymore - switch to sgminer.
sgminer doesn't support Gridseed
Well, what we're seeing here with this cgminer-3.7.2 is similar to WinXP story ... to many users of too old software, and when support ends it's "Houston, we've got problems"

Anyway, the correct path would be to adopt newer software. The absolute correct path would be for the GridSeed community to step together and build modular approach for GridSeed support in sgminer/bfgminer so that it would be easy for veox/luke-jr to include support for GridSeeds in upstream versions. Not sure how to accomplish that though, community/gridseed users should step together for this.
See FAQ "Which miners are supported?"
https://www.nicehash.com/index.jsp?p=faq#faqs0 (BFGMiner is supported)
And if you really want to use cgminer, cgminer-3.1.1 (this version doesn't yet introduce the xnonce2 bug) is also supported (
https://github.com/gridseed), but I really don't recommend to use these old versions.