Duration of I-94 on R1 visa.

[jonrowsell]

I am in the US on an R1 visa, and my I94 duration stamp is valid for longer than my visa. I understand that the stamp takes precedence, but is it usual practice for the I94 to be longer on an R1 visa? I know one other person on an R1, and their I94 is valid for only the length of the visa. I'm planning to leave and re enter the country soon (while my visa is still valid) but I'm struggling to find out what the usual code of practise is with regards to I-94s - when I re-enter will they again give me a longer I-94, or will they only validate my duration of stay for the length of my visa?
If anyone else that has an R1 visa could let me know what they've found with their I-94s, that would be very helpful.