With StarCraft 2 being so heavily integrated with Battle.Net, gamers who purchased the game are becoming frustrated with the way in which the game stores single player progress when logged into Battle.Net. Currently gamers are losing achievements and save game progress which has only just come to light as more and more gamers progress in the single player campaign.
As players have progressed through the campaign, unbeknown to them, they have been disconnected from Battle.Net while playing, or their PC may have crashed. However, although the game saves locally to the hard drive, the information is also sent to Battle.Net which stores the save progress and achievements, and if connection is lost to Battle.net, the save and achievement information is also lost.
With no message to say you have been disconnected from Battle.Net while playing the single player game, some gamers have lost hours of gameplay time only having to go back and redo missions.
RTS gamers will remember the problem with losing mission progression when connection was lost to EA’s server, and while there was a workaround eventually, this caused huge headaches and made the single player game irritating to play if the connection was lost.
Blizzard has not yet posted a solution to this on their support forums.