Since Randy has admitted that the episodes have become a blur, I am VERY HUMBLY going to offer my own recollections on complete chain banking.
The $125K was reached and banked once on the network version--I'm pretty sure that's what the WMV file previously linked to is a clip of. However, on the TV Moms edition, a $75K chain was banked--followed by a right answer, which is painful enough--and then a $50K chain was subsequently run. The next celebrity failed to bank . . . AND missed her question. (Anne rather humorously had to explain the addition to her.)
In the syndie run, $12,500 and $25,000 chains were run often enough that, by the middle of the second season, I would say it was no longer a "SPOILER!!" event. However, there was a close call in that version as well--a contestant failed to bank a full chain, but managed to come up with another correct answer with two seconds left on the clock. You could hear the audience holding their breath to see if the frantic "BANK!" that followed was in time or not. (It was.)
Oh, and I vaguely remember a syndie episode where a contestant inherited a $5,000 chain (5 of 6 links) with 3 seconds left on the clock, and failed to realize she needed to bank until after George had begun the question. "That bank was too laaaate . . ."