Dell Inc.'s (NASDAQ: DELL) troubles might look like they're turning around. But there's still a problem with the numbers.

Although the company lost quite a bit of share to rival Hewlett-Packard Co. (NYSE: HPQ) in its latest quarter, the return of founder Michael Dell to the helm as CEO is starting to play out. The company has made some remarkable changes since Dell returned in January -- it recently went back into retail in a partnership with Wal-Mart Stores, Inc. (NYSE: WMT). And the company posted better-than-expected profit for its latest quarter. One quarter, though, does not a turnaround make, right?

It's been almost two years since the SEC launched an investigation into Dell's accounting and financial reporting matters, to which Dell replied with its own internal probe a year ago in August of 2006. The internal probe of financial shenanigans is allegedly coming to an end, but there are questions remaining. Dell shareholders have put up with a cloudy picture of the company's actual performance all the while. They can't be too happy about this.

Now comes a request from the U.S. Attorney's office (Southern District of New York) to look at Dell's accounting procedures and reporting back from 2002 to the present and there may be more to come with Dell's financial reporting soon. It's good to know that its own internal investigation is almost complete, but that is probably far from the final picture of just what happened inside Dell's accounting arena.