Rails clock lags


after several hours of use (~100 hours), clocks of my fcgi scripts
starts to desync with system clock.

IS it a bug in ruby/rails/fcgi or is there something like a memory leak
which pushes clock earlier and earlier. is there a way to change clock
within Ruby? Maybe I am manipulatiing time but am not aware of it by
using that function.

any ideas?

thanks in advance