Paul Thurrott last week reported that some Windows Phone 7 users were seeing unexpectedly high levels of data usage. It's now being reported that Microsoft is investigating the issue.
The problem appears to be that some Windows Phone 7 handsets are sending large amounts of data, and opting to do so via 3G even in the presence of WiFi; the result is users burning through 2GB or more of data a month. Thurrott describes the issue as "curiously common," though it's certainly not universal. He has been tracking his data usage, but has no real explanation as to why it has increased with each month—there's nothing obvious that's causing the data usage.
Personally, I'm not seeing any such issues; since I started to use Windows Phone 7 my data usage has certainly gone up, but that's because I'm legitimately using the data connection more extensively. My increased data usage (a couple of hundred extra megabytes a month) is in line with what I'd expect, given the change in usage patterns: I'm performing much more mobile browsing than I was with Windows Mobile 6.5, I'm using the Maps program regularly, and I'm syncing mail from four accounts now that I can use multiple Exchange accounts simultaneously. We'd love to hear from any readers who have experienced the issue and can shed any light on the problem.
If Microsoft does confirm that there is a problem with Windows Phone 7 that's causing excessive data usage, it'll be another item to add to the list of things that the company needs to fix on its new smartphone platform. Though the company has promised an update to support copy-and-paste is coming soon (perhaps coinciding with next month's Mobile World Congress), it has remained frustratingly tight-lipped about what other updates and fixes are in store, or when they will materialize.