dos device failed while playing my game

the only game i play at mo on pc is rainbow six vegas , when i play it two mins down the line or could be a n hour or so it crashes saying dos device failed insufficient resourses to complete the tasks , it then goes back to desk top mode and is at a less resolution than before , i have to reboot sometimes to get back to norm. i have an asus eax1950pro graphics (ati radeon)amd 4200x2 1gb memory (ddr400) i have done all up dates inc bios to try and solve but i cant seem to find out whats wrong . ive attached my dxdiag please some one help im sick of playing online and getting right into it then it crashes