Got this from their blog, take a look:
We have had a lot of questions about Battlefield: Bad Company 2 on all platforms about the issues some have had. Here we will answer some of the more common questions, some will help you get in game, others will give an insight to what we are working on.
This Q&A isn't a definitive list by any means and we are aware of and are working on more than these issues:
Connection issues to EA servers
EA Online has been adding more capacity to handle the high number of player connections to EA servers. This is an ongoing process but we currently have enough capacity to handle all BFBC2 connections.
Manually install PunkBuster on PC
If you are getting an error that Punkbuster hasn't installed correctly for reasons such as Windows admin permissions not allowing Punkbuster to be installed, then go to
www.evenbalance.com" onclick="window.open(this.href);return false; and download PBSetup.exe. When prompted, point PBSetup at your BFBC2 install directory and then check for updates. A PC restart maybe needed once this is done for Windows to pick up Punkbusters location.
PunkBuster kicks with the following error message : « punkbuster kicked player 'PLAYER NAME' (for 0 minutes) ... RESTRICTION: Service Communication. »
This is a Windows Vista/Windows 7 permissions issue that affects all Punkbuster games. To solve this issue download and run PBSVC from
www.evenbalance.com/downloads/pbsvc/pbsvc.exe" onclick="window.open(this.href);return false;
When clicking on a server to join, nothing happens.
This is fixed in a patch going out on PC today.
Server Browser bugged: All the following browser issues are things the team is currently working on improving.
Too slow This is caused by the current browser system. - A new system is being developed by the BFBC2 PC team to improve the server browser
Displaying inaccurate number of players connected on game servers - This is caused by the difference in server status between when the refresh was initiated and when the results display.
No ping displayed - This is caused by Windows admin privileges. To view ping in the server browser run BFBC2.exe with administrator privileges.
High pings even on local game servers. We're actually showing game latency instead of ping.
This is basically how far behind the client is compared to the server. We try to keep the server a small portion in front of the clients so they in most cases can use replicated data until they get the next ghost update from the server. If they get a lag spike they will start predicting the state when they run out of information, however, the basic idea is to smooth out the experience compared to everything having to be corrected when the predictions are slightly off.
After being disconnected, some people got their stats temporary reset.
The team is investigating this issue, we have no solution at this point. Please report any stat loss here:
forums.electronicarts.co.uk/battlefield-...ing-stats.html" onclick="window.open(this.href);return false;
When people try to reconnect to their profile, the game asks for the serial number again
This has been fixed on the entitlement side hence no patch is needed. A really small number of people got affected by this.
360 accounts will be “reset” this weekend?
This is a rumour
Some players have had trouble redeeming their VIP codes
This should have cleared up now, the in game store on PS3 for Europe and Asia is coming soon.
UPDATE
If your seeing random server disconnects after playing for some time ~20mins on Bad Company 2 servers try disabling UPnP on your router.
But the M14 is basicly the same as the M1, only modified. 
