SAN FRANCISCO (CNN/Money) - Call me crazy, but when the tech market is rolling along as it is these days, I get a little paranoid.

Not black-helicopters-are-following-me paranoid, but I know a black cloud can form in even the clearest sky, and I don't like to be surprised by storms.

History shows that the number of IPO filings is inversely proportional to the quality of diligence conducted by investment banking firms on Wall Street. Usually diligence is fairly strong when the IPO market first begins to simmer.

But eventually, we hit a tipping point where the IPO fees and proceeds the banks collect are too great an incentive, and diligence takes a back seat to the quick buck.

I think we're getting closer to that tipping point. Brad Hintz, an analyst with Bernstein, characterizes investment banks' current attitude toward IPOs as "enthusiastic," but he doesn't think we've reached the tipping point.

"We haven't seen yet any of the bad due diligence which was so prevalent during the boom," he says. "Of course, you can always find an exception."

I've found two: Claria and Lindows. Both companies filed to go public this month. Let's take a look.

Claria operates a "leading online behavioral marketing platform that...deliver[s], manage[s] and analyze[s] highly targeted online advertising campaigns," according to its Securities and Exchange Commission filing.

Never heard of it? You might know the company better by its previous name, Gator. That's right, it's the company behind those awful pop-up and pop-under spyware ads. This is a company whose primary product is so reviled by the public that a cottage industry has emerged with the singular goal of eradicating Claria's main revenue source.

"Ah yes, everyone's favorite company," says Jupiter analyst Nate Elliott with a laugh, when I ask him for his thoughts on Claria.

Though Elliott is quick to point out consumer hatred for the company's products, he also mentions that "advertisers love Claria. I haven't talked to one advertiser who uses Claria that wasn't happy with the results."

And to be sure, Claria's filing shows some decent numbers: Last year, the company made $35 million on $90 million in revenue. Not bad.

However, Claria is on the wrong end of consumer sentiment and faces some major litigation and legislation issues. Nine lawsuits against the company are currently in the courts.

What's more, Utah just banned the use of Claria's products, effective May 3. And the Federal Trade Commission is now investigating the issue of spyware.

Despite Claria's atrocious consumer image and rocky future, it at least makes decent margins on respectable revenue. The same can't be said of our "1999 all over again" award winner, Lindows.

Lindows offers a desktop version of the Linux operating system and filed to go public on April 20. Its total revenue for 2003? About $2 million. The company reported a loss of about $4 million for the year.

"I just don't understand Lindows's business model," says Charlie DiBona, an equity analyst with Bernstein. "Linux on the desktop for the everyday user is going to have low penetration."

Neither DiBona nor Bernstein owns Microsoft shares, but Bernstein's parent company, Alliance Capital, does own shares in Microsoft.

With that kind of revenue, I just don't understand how this company could be taken public, though I have a pretty good idea why.

Company founder and CEO Michael Robertson, who previously founded and took public MP3.com, lent Lindows more than $10 million of his own money to start. Given the company's current sea of red ink, staying private means it'd take a long time for Robertson to see that $10 million again.

The company's SEC filing says that some of the proceeds will go to Robertson to repay this debt. What's more, Robertson and the other company directors all granted themselves huge raises this month. As CEO, Robertson was making $14,040 a year prior to April. Now he's making $410,000 per year.

I've known Robertson professionally for six years now. And I know that he's actively engaged in a new company he's started, SIPphone -- a voice-over-Internet-protocol outfit.

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Lindows's IPO could be a tactic to repay the company founder so he can move on to other pursuits. Of course, when you're competing against Microsoft, which is sitting on $50 billion in cash reserves, you do need capital, which is the official reasoning behind Lindows's IPO. But neither Robertson nor other company representatives would comment on the record, citing SEC quiet-period restrictions.

In the first half of 2003, only 10 IPOs were priced. It was the worst clip since the second half of 1975, according to Rich Peterson of Thomson Financial. Already this year, more than 100 companies have filed to go public.

While most analysts insist diligence is still in fashion on the Street, these exceptions do exist. As a result, investors need to spend more time researching their prospects.

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