The particular rule about visits to Canada and Maxico "not resetting the clock" applies, as far as I know, only to the Visa Waiver Program, and not to travelers with visas.
However, even if it did, I can't see how it would create any problem for you, since your final exit from the US will only be about a week after you first entered. No matter whether any clock is or is not reset, this is by all means an unproblematic short visit.
You will have a problem if your B-2 visa only allows a single entry, though -- since your plan clearly involves entering the United States twice. But that is not connected to any "resetting of clocks". Even under the VWP rules, the result of the neighbor-country rule is not that you "did not leave the US and reenter", but merely that at your admission the second time you enter will be limited to until 90 days after the first entry. Both entries are real entries, though.
However, it seems to be quite rare for B-2 visas to be issued for a single entry only. The visa does have an "Entries" field, but all examples I could quickly find on Google Image Search showed this fill out with M(ultiple). There are scattered claims on the net that certain nationalities are more at risk for getting a single-entry visa, but no hard data.