If any of you shopped at a DSW between mid-November and mid-February, your credit card or check information may have been stolen. At 108 of their stores, customer information was stolen. Here's the press release from DSW; it also has a link to the list of stores: http://www.dswshoe.com/pressRelease.jsp
My wife and I had some unauthorized charges to our credit card in late March, and I think this was the source of obtaining our information. So, to state the obvious, be careful and be sure to check your account activity online often (it helped us catch the unauthorized charges early).
I'll second that catching it as soon as possible after the fact is very important, because after a certain amount of time (which varies from issuer to issuer) they won't consider issuing a chargeback for a fraud. The exception may be if it was the card issuer's fault, like allowing a charge on a closed account.
It could also be that your Recycle Bin hit the limit where it recovers space. Your drive could have been incorrectly listing the free space available, which could have been fixed after a scandisk. Perhaps you cleared the cache in Internet Explorer?