Yeap, I'm having the same old problem again. I checked SERPBook.com and it showed that my site is ranking first for a very competitive keyword. But when I check in my computer using Chrome's incognito mode, my site wasn't first but at the 5th page (45-48th position). Checked my rankings in one of my old VPS located at Canada, it shows 7th page (68th-70th). So who to trust? And yes, I've logged out, cleared all cache, and even use incognito... so I'm NOT logged to google account. From my past experience, I thought this was caused by a lack of update/cache to other google servers; therefore, one of them is right, but just haven't update to the rest of Google servers. So what do you think? There's a chance for it to go back to first, right?