No network problems here.

That said, I've experienced the same situation as you in the past (months of reliable 3G service followed by sudden network instability). Customer care can usually confirm for you if there are network outages in the area and if it is due to something on their end. In my case, they were able to confirm the network disruptions for me and could attribute it to T-mobile USA upgrading the HSDPA network in my area. Sure enough, network stability returned in a week or so, with an upgrade to reliable 3.5G...