REDFACTION ONLY! (HELP PLS)

Hey!

Im Running A: AMD ATHLON T/B 1.4GHz
512 DDR
etc… 56k V.90 Motorola SM56 Modem
and when i play redfaction multiplayer i get these to pcs come up ever now and then and they have a cross through them and it pauses the screen if u know wtf this is please help Thanxs!