I've just leased GSD0 and GSD2, mining at wafflepool.
Both rigs has over 10% rejects at the european server, us-east is much better. Where are the rigs located?
Edit:
Switched back to the european server and now it's better, maybe you had trouble with your internet connection? Wafflepool servers has been very reliable (I'm mining there with some gridseeds). Hashrate at leaserig.net for GSD2 is much too high at 11 MH, but pool rate is correct.
The rigs are in the UK. GSD0 is 20 gridseeds, GSD2 is 4 gridseed blades, however right now only 3 are working properly due to one of the PSUs being faulty, I should have that resolved soon, but this is why when you rented the rig it was rated at 8.4Mh, not 11.4Mh. If I get it working then you'll benefit from the extra 3Mh/s free of charge.
Reject rate seems fairly normal to me. I've been sitting here watching the shares go by on both rigs for the past 5 minutes and there are lots and lots of accepted shares, and maybe the odd one that is rejected. Since wafflepool is a multi-pool, it's possible they were mining a quick coin or something that pushed the reject rate up. It happens. From my side however, everything looks nice and stable.