You can contact sinistar through the e-mail address which he sent you Gravematter from or go to www.uberdroid.com and there should be contact information there.
I would not worry about it too much at the moment.I am sure that Sinistar is just waiting for a stable,final-ish version of FPSC before he fixes the stuff in question.There would be no sense in fixing it now when v1.05 could come out tomorrow and it may not work again.
There are other work arounds to this too.Like opening the said entity in a modeling program and seeing if you can fix it yourself or re-importing it into FPSC or something like that.
Remember to backup everything before you try that and if you aren't real sure about what you are doing just wait until Sinistar posts a fix for it.