Have installed sp1?
Well I know I am a little late, but maybe this helps someone struggling with this, like I was today.
Firstly, "type id filed" is definitely name of the field that holds subtype.
It seems that this field is blank in feature service in case you do not have used if for symbology, or better to say to for your Feature Template. Basically if you have feature template for editing for every subtype, you will have correct type id field name and everything considering this just fine as in map service. But if you have feature template for single symbol, you will not get typeId field from feature service.
I have to admit that I cannot see a good reason for this, but that is another story...