Last April, Microsoft met with criticism when it announced that it would deactivate all music purchased from MSN Music. Customers rightly protested that the decision to pull the plug on the Digital Rights Management (DRM) servers that allow MSN Music customers to “reauthorize” music files would render their purchases useless

At the time, EFF announced an open letter to Microsoft, urging them to make things right with their customers by giving refunds or replacing DRM-crippled music, and by avoiding use of DRM in the future.

Now, Microsoft has responded to their customers’ concerns with a letter to customers that promises that the earlier deadline of August, 2008 will be not be enforced. Instead, the company will wait until 2011 to make a determination.

“After careful consideration,” the letter reads, “Microsoft has decided to continue to support the authorization of new computers and devices, and delivery of new license keys for MSN Music customers through at least the end of 2011.”

Paying customers of Microsoft’s MSN Music store can breathe a sigh of relief, but the real problems remain unaddressed. DRM-crippled music still has an expiration date –- whenever the company that sold that music becomes unable or unwilling to continue supporting the copy protection.

Hopefully, Microsoft and other digital music vendors are learning an important lesson from all of this: DRM copy protection is not just irritating and cumbersome for customers, it not only does nothing to prevent piracy — it's also a burden on the companies that build and support the DRM.

It’s not as if this sort of thing hasn’t happened before. Last year, Sony’s abandonment of its proprietary ATRAC music format caused the same problem, with paying customers forced to burn and re-rip music in order to save it. Around the same time, Google ended up refunding purchases of DRM-laden videos purchased through its Google Video store when it decided to shut the service down.

The choice for online music vendors is clear: Sell music crippled by DRM, and you'll either be stuck supporting obsolete technology for years to come, or else be obligated to hand out out refunds to customers made doubly unhappy by content that doesn’t work well, and later doesn’t work at all.