nginx worker process wont start

[rkmr.em at gmail.com]

i get this error and it fails to start, i have 8GB free ram

2008/05/21 08:02:19 [emerg] 30558#0: setuid(500) failed (11: Resource
temporarily unavailable)
2008/05/21 08:02:19 [alert] 30557#0: worker process 30558 exited with
fatal code 2 and can not be respawn


free -m
             total       used       free     shared    buffers     cached
Mem:         16086       7796       8289          0         80       4697
-/+ buffers/cache:       3018      13068
Swap:         1983          0       1983