Problem with MV 3.15 on www.minivend.com?

[Dmitriy Katsman <dmk@affordablecomputers.com>]

Hey everyone:

quick question... how to order multiple items?
I always thought something like:

http://www.minivend.com/cgi-bin/simple/process?mv_order_item=00-342&mv_separate_items=1&mv_order_item=99-102&mv_todo=refresh

and now do RECALCULATE or CHECK OUT.... or just click on
SHOPPING CART again....
pretty funny, huh?

must work.. but it doesn't... see what it does for yourself... it kind
of RESETS your cart (if you had something in it before... it disappears
after doing refresh after the above URL)

am I doing something wrong???
I think that method to purchase multiple items always worked for 3.14
and below... but not working for the last version...

can anyone please help me fix it? I got 99% of the site written using
3.15 (because I needed on-the-fly items), and now THAT...

Thanks a lot in advance,
Dmitriy