problem with multiplayer

can some one help me with multiplayer, when me and my brother try to connect it always ends up one of us getting a connection error or just the nintendo sign and it freezes please help

Post in the correct section in future, do not hijack other threads. Split and moved.

Which system? We can't really help you unless we know what we're working with here.

Some games do not support download and play on the R4 is thats what your trying to do.....

I will assume you're using a Slot-2 device because you mentioned freezing at the Nintendo logo. Slot-2 devices (ones that go in the GBA slot) like the M3 or the Supercard often don't work for download play and freeze at the Nintendo logo. If you use a passcard and a Slot-2 device, you can flash the firmware on the DSes to a hacked firmware which has much better compatibility with download play. 99% of the time Slot-2 users can only use download play with other flashed DSes. If you're interested in flashing you're DSes PM me for an explanation on flashing, otherwise if you buy a Slot-1 device such as the R4 or the M3/G6 Real you will have much better compatibility with download play.