Taken from the www.linuxcounter.org
"The Linux kernel (at least up to 2.4.2) has a flaw: It computes the result of the "uptime" based on the internal "jiffies" counter, which counts the time since boot, in units of 10 milliseconds.
This is typecast as an "unsigned long" - on the Intel boxes, that's an unsigned 32-bit number.
Well, it turns out that in a 32-bit number, you can store 497.1 days before the number wraps"
You could write a script real_uptime.sh to add 497.1 days to the output of uptime as a quick & dirty solution and set
Congrats on having such a reliable system..