Nick
V29 working fine here on both complete and part circles/arcs, Build 2192, the original V29 download, not been updated
Sounds like you need to get some of your moneys worth for that support package of yours It would be pretty useless IMHO if it won`t put a point to an arc centre or won`t place a tangent line from a complete circle !!
Just my 2 cents worth
Regards
Rob