It may soon be time to update your maps of Southeast Asia, or at least, have Google Earth update its maps. In 1983, Vietnam and Cambodia made an agreement to work out the exact border between them, as their border had never been clearly defined. They had made on-and-off attempts to talk during the 1960's and 70's, but the Vietnam War got in the way. They've been talking ever since, using a neutral border made in 1954 as an interim solution.
It's been pretty slow going. As the above linked article notes, as of 2005, 22 years later, only 200 km out of 1,137 had been sorted out as of the time of a ratification of a supplementary treaty. Last year, the two resolved to pick up the pace.
But pace can go out the window when nations are talking about getting or giving up land. One politician in Cambodia, Sam Rainsy, had to go into exile in France in 2009 after convincing residents living on the border to pull up border markers placed by Vietnam in protest. Rainsy is the leader of the main opposition party in Cambodia, the Sam Rainsy Party, and is dissatisfied with the supplementary treaty.
That supplementary treaty is why Cambodia finds itself negotiating to try to hang on to the villages of Thlok Trach and Anlung Chrey in the province of Kampong Cham. Reportedly, they would have to give up two other villages to keep them, though it's not specified which two and they may not have been decided upon yet. Anlung Chrey is of particular importance, because it happens to be the hometown of Heng Samrin, the leader of the National Assembly, Cambodia's lower house of parliament.
You've heard of politicians trying not to get drawn into an unfavorable constituency before, but it's a little different when they're trying not to get drawn out of the country entirely.