To shed a little light on this issue, the problem is not that chargers want Gates to just play for 380k. The Chargers offerd Gates a five year contract slightly less than Gonzo money. Gates (or his agent) want more money than Gonzo and only said that they would take less if the contract was only for three years. The Charger want a five year contract.
http://sports.espn.go.com/nfl/news/story?id=2129144
They did not just offer him 380k to play this year. They offered him what they though of as a more than fair contract based on his one year probowl performance, but Gates or/and his agent do not agree.
The chargers are just trying to get gates to sign the tender and get into camp that way they have more time to get a deal done without havng gates miss most of the season.