Prime: Know it all?

When Prime is telling Sam about how his great grandfather found Megatron in 1897, he tells it in such detail ("he accidentally activated Megatrons navigation system"), as if he was there under the ice with them... Now, I know the Autobots are aware of the glasses and all from eBay, but how is Optimus privvy to the details that he tells Sam?

I think Sam's great granddad (or whatever) wrote it all down in his diary/log entries, which in turn ended up in the government archives and internet.

That's my guess anyway. TF is full of plot holes.

Remember Bumblebee was sent there to scout it out.

Bumblebee made a net search of any clues to the Allspark.

When he found out Archibald's scribbles and description of the Ice Man ,he tried to find his decendants.

Prime is likely familliar with Megatron's operating system noting that Megatron must have uploaded data into Archibald's brain.

Well since Archibald is pretty much dead his glasses are next best thing as to where the Allspark crashed.

Well right on! That all sounds good, thanks you two...

Yeah it really is, but I still enjoy it for what it is... entertainment and a couple hours of escape-ism.

But I find the biggest problem to be not a plot hole per se, but bad story writing. The whole ending revolving around Sam having to protect the AllSpark is ridiculous considering the first 3/4 of the film the Autobots are adamant that no harm be brought to the humans, yet in their most desperate hour do any of them take on the task of protecting the cube? No. Bumblebee handing off the cube is excusable because he just had his legs blown off, but why did Ironhide and Ratchet merely swear to protect Sam as he dangerously has to make to a rooftop to hand it off to MORE HUMANS??? Either IH or Ratchet should have manned up and taken the damn thing themselves!

Ironhide and Ratchet would be easy targets, due to their size. They needed Sam to make the run because he was small, and harder for megatron to track.
Megatron can take any autobot in a one-on-one fight. Do you think Ironhide would be able to outmaneuver megatron, or hide from him? Could Ironhide hide inside a building?

It was just a hipothesis. Part of something magical called scientific method.

Good point.

big deal... generation one has even more plot holes

My only plot issue was how the location of the Hoover Dam was etched into the glasses in the 1800s.

it wasn't the location of the Hoover dam, it was the location of the Allspark, which humans built the dam over to hide its energy signature.