Drugstore stocks are trying to perk back up.

Days after Walgreen ( WAG) hurt the entire sector with a rare quarterly miss, both CVS-Caremark ( CVS) and Rite Aid ( RAD) offered soothing news about their own recent performance.

CVS-Caremark enjoyed a 5% jump in same-store sales last month due to strength in its pharmacy and front-store businesses alike. Rite Aid reported a much smaller 0.7% rise in same-store sales, but the company's pharmacy business -- a key focus right now -- grew at almost twice that rate.

Investors seemed relieved. All three drugstore stocks, including battered Walgreen, posted modest gains on Thursday.

Meanwhile, many experts have decided that Walgreen suffers from unique -- and perhaps temporary -- problems that are not contagious at all. Walgreen itself blamed much of its recent setback on falling rates for normally lucrative generic drugs. But others see a company failing to properly manage its rising expenses instead.

By now, William Blair analyst Mark Miller feels that Walgreen has been punished enough.

"We find it intriguing that the company was not being valued as a 20% grower commensurate with the performance during the first three quarters of fiscal 2007," Miller observed on Tuesday. "Yet the stock appeared to be fully punished for the shortfall during the fourth quarter" as if it were.

"In any event," he added, "the absolute and relative valuation of the stock is at a 10-year low, suggesting that expectations are low. To the extent that the market has overreacted to what may be -- in significant part -- an anomaly in the way quarterly results flowed through fiscal 2007, long-term investors are likely to be rewarded buying the shares on weakness going forward."

Miller, who has an outperform rating on Walgreen's stock, appears to be taking his own advice. His family owns shares in the company itself.