Backup storage specialist Quantum (NYSE: QTM) probably wishes it could restore reality to an earlier backup, from when things were going well.

The stock is trading down 27% from where it sat a couple of days ago, on the eve of its earnings release. That action has erased about three months of gains, resetting Quantum to about the same levels it enjoyed a full year ago. So ends one chapter in the company's turnaround saga.

Sales dropped 3% year-over-year as a recently introduced series of disk-based backup systems appears to have confused Quantum's customers -- the company is typically all about tape-based storage. The disk-centric systems are faster than tapes, but they also command a significant price premium compared with older Quantum solutions or with equivalent systems from Data Domain, which is now a part of EMC (NYSE: EMC).

The big question now is: Are those hesitant customers going elsewhere for their backup needs or simply pushing back their big buys into the coming quarter? The former would be a disaster for Quantum, while the latter would make the past two days' share implosion a real buy-in opportunity as those fortunes reverse in coming periods.

Management sidestepped the issue by sticking its guidance close to seasonal trends. There was also no guidance adjustment or preannouncement made to ameliorate the impact of this shortfall, a fact that analysts on the conference call found mindblowing. If I were a Quantum shareholder, I would also be taken aback by this lack of transparency around an important issue.

Look around the storage sector and it's easy to find more attractive investment opportunities than this spin-tinged disaster area. EMC and NetApp (Nasdaq: NTAP) are the obvious choices in storage systems, depending on whether you prefer stability or growth. Disk manufacturers Seagate Technologies (Nasdaq: STX) and Western Digital (NYSE: WDC) are even cheaper and possibly due for a bounce one of these days.

You can add Quantum to your watchlist to keep your finger on the company's erratic pulse.

Fool contributor Anders Bylund holds no position in any of the companies discussed here. The Fool owns shares of EMC and Western Digital. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. You can check out Anders' holdings and a concise bio if you like, and The Motley Fool is investors writing for investors.