WASHINGTON - The United States and Russia will proceed this week with a complicated and unprecedented spacewalk outside the international space station despite a last-minute dispute over the use of Russian equipment that threatened to delay things for a day, NASA engineers said yesterday.
MSNBC

The reason they are using Russian space suits is because the US space suits cooling system failed, but an earlier EVA ended prematurely due to a Russian space suit cooling system failure.

If a real emergency arose and an immediate space walk was the only cure, those astronauts could be in trouble if they don't get a handle on the space suit glitchs.

SteveS