Which number is it?

Sen. Arlen Specter (D-Pa.), in his harshest attack on primary opponent Rep. Joe Sestak (D-Pa.) to date, accused him of missing 122 votes in the House. Or is it 125?

In a letter addressed to Sestak today, Specter suggested he resign from Congress or step out of the race because of his missed votes. The letter said that he skipped 122 decisions?

But in a tweet mirroring the dis on Sestak, Specter accused him of missing 125 votes:

Rep. Sestak, it's time to decide: Serve or quit -- candidate or Congressman. With 125 missed votes, you can't be both. http://bit.ly/Il5s3

The Washington Post's congressional votes database says Sestak has missed 125 votes. But GovTrack says he has missed 122 votes.

So, which number is it?