Some of the beta testers for Microsoft's Windows Live Hotmail service are getting an increase in storage, but the extra capacity isn't being introduced as smoothly as some of them might hope.

The users will see from their storage meter that they now have 4GB of storage, up from 2GB before. But the extra storage might not actually have been assigned to their accounts yet, according to a company blog posting.

"This seems like putting the cart before the horse," the posting says. "The reason for this is that the storage upgrade is being gradually rolled across the universe and does not immediately change every account at the same time."

The problem should resolve itself as the upgrade continues over the next two weeks, Microsoft said. The expanded storage is only for "Hotmail Plus" customers who are beta testing Windows Live Hotmail, a revamped version of the company's Web e-mail service.

Hotmail Plus customers pay $19.95 per year for a 2GB account and extras such as the ability to send 20MB attachments.

Microsoft's free Hotmail service offers 1GB of storage and a 10MB attachment limit. By comparison, Google's Gmail offers 2.6GB of storage for free and Yahoo's free e-mail includes 1GB of storage.

Last month, Microsoft rolled out another feature upgrade, M10, for the Windows Live Hotmail beta, which is supposed to improve its speed and reliability.