I have encountered this problem twice and have corrected it by flushing coockies and caches from IE (i also used Mozilla mac/pc and even safari)
Invalid variable value : offset = -6460941
(this the last, the number keep changing)
Worst, as i'm inviting other people to check the site some got error some not... It is a ratio near 1/2 i can help them for now cause there are few and they help me to set the site but when it will be wide open it will be a pain in the... as i have 35 000 hit each month to deal with.
Does anyone encountered this error and where shoul i look.