Updated from 10:49 a.m. EDT

It's a little early to be thinking about Halloween, but there is already a creature lurking about like the walking dead -- apparently devoid of life and yet impossible to kill.

I am talking, of course, about

TiVo

(TIVO) - Get Report

.

For the past couple of years, many TiVo-watchers have been ready to write the company off as dead. TiVo was supposed to be a latter-day Netscape, a hot start-up that pioneered a radical new technology before seeing it taken over by other, deeper-pocketed rivals. This school of thought sees TiVo dying away with a whimper, not a bang, forever immortalized as a footnote in television history.

Despite a new burst of confidence among sunny-minded investors that has driven the stock up by nearly one-third in the past three weeks, the TiVo naysayers remain a powerful lot. They have built up the number of TiVo shares sold short to 16.3 million as of Aug. 10, the last data available. That's nearly one in five shares in TiVo's float.

The thing is, TiVo refuses to die. Its managers are as inventive as they are resilient. Its programming and recording software continues to be head-and-shoulders above its rivals' in terms of ease of use and intuitiveness. And as old relationships die away, it keeps forging new ones, like the deals with

Radio Shack

(RSH)

and

Cox Communications

.

TiVo's stubborn tendency to come up with cunning new strategies showed itself on Tuesday, when the company said it's allowing its subscribers access to CBS' new comedy "The Class" a week before it's aired on the broadcast network. (This news drove the shares up another 3.2% on Tuesday, but they fell nearly 4% on Wednesday after an announcement that the company planned a follow-on public offering of 8.2 million shares).

All of which explains the sense of ambivalence that the Street has been feeling since TiVo

reported its second-quarter earnings last week, posting a loss that was worse than the one posted a year before, but one that was only about half as bad as anyone (including TiVo, judging from its earlier guidance) was expecting.

Since then, TiVo's stock has been seesawing according to the mood on Wall Street. After edging down a bit before it posted its second-quarter numbers, TiVo shot up nearly 8% the next day to $8.25, only to fall 4.2% on Friday to $7.90. On Tuesday, it climbed to $8.15.

Meanwhile, analysts have been stacking up TiVo's pros and cons like so many weights on either side of a scale. Yet the scale refuses to swing decisively in either direction.

Among the cons: TiVo continues to hemorrhage users who signed up through

DirecTV

(DTV)

, which set up its own digital video recorder in 2005. In the second quarter, the net loss of DirecTV subscribers was 29,000. That left TiVo with a net gain of only 1,000 total subscribers in the quarter, compared with 254,000 new subscribers in the year-ago quarter.

What's more, TiVo's costs are likely to grow at least for a quarter or two. According to Kaufman Brothers, TiVo's spending per new subscriber (excluding the DirectTV losses) rose 48% from a year before.

Given the company's "intention to begin more aggressively promoting its service this holiday season, net losses are expected to increase significantly over the next couple of quarters," wrote Kaufman analyst Todd Mitchell in a report. Kaufman has no underwriting relationship with TiVo.

But Mitchell also outlined several things in TiVo's favor: The company is starting to bring in revenue from its fledgling advertising business, having signed deals with two of the three top ad agencies. It lined up the deal with Cox for a downloadable DVR service and found a presence inside 3,000 Radio Shack stores. And it gained some ground in its legal battle with

EchoStar Communications

(DISH) - Get Report

.

All that positive news has been priced into the stock, as has any benefit from TiVo's apparent ability to keep marketing spending and legal costs lower than it had planned. And few expect any strong improvement in the current quarter. So, Mitchell and other analysts are sitting and waiting to see what happens starting around Christmas -- and into 2007.

"The fourth quarter is the critical test of management's new strategy," said Steven Frankel, an analyst at Canaccord Adams. "By then, the new Series 3 box will be available, and a significant amount of marketing is likely to be needed to win the hearts and minds of consumers and retailers."

Frankel also noted that the deployment of TiVo into

Comcast

(CMCSA) - Get Report

set-top boxes should begin in the fourth quarter and continue to roll out through early next year. Canaccord Adams has no underwriting relationship with TiVo.

It seems TiVo has bought itself another few quarters of wait-and-see from Wall Street -- enough to let it lurk through Halloween, Christmas and maybe even Groundhog Day.

In the meantime, the longs and shorts will duke it out, although the longs' current upper hand could mean little upside for Tivo's shares, at least in the short term.

That may knock the company's stock down, but it's too early to count it out.