GMail times

Some days ago I noticed that GMail is giving weird timing information. This is related to what is shown on the top of the message (yyy minutes ago). Most of the time now they turn out to be negative!! I think they have started using clock reading from the user's computer to stamp their mails. So in case if some one has a time set in future, it gives -ve date. I dont think it was this way earlier, the time stamps *should* be taken from a known, correct source! Google please change this!!