It always pays to read the fine print. Even then, however, you might not get the whole story.

Sign up for SBC’s National Connections plan and you’ll get unlimited long-distance calling for just $20 a month.

Unless, that is, you «misuse» the plan by failing to meet its various requirements, in which case you’ll be shunted to a program that charges a whopping 21 cents a minute for long-distance calls.

Or sign up for one of SBC’s various JustCall plans and pay as little as 5 cents a minute for long-distance service.

Unless, that is, you stop using SBC for your local calls as well, in which case -- yup -- you’ll be shunted to a program that charges 21 cents a minute for long-distance calls.

These risks aren’t detailed up front in SBC’s promotional materials. The fine print of the National Connections service says only that «customers will be moved to a higher-priced, per-minute long distance plan» if they no longer qualify.

The JustCall fine print, meanwhile, makes no mention of a potential penalty. Customers who order the service via SBC’s Web site will be informed of the 21-cent rate only after they’ve committed to the plan.

JustCall and National Connections comprise the bulk of SBC’s domestic long-distance plans.

John Britton, an SBC spokesman, acknowledged that details of the costly charges aren’t included in the company’s promo materials. But he said customers who order by phone will be warned in advance by the sales rep.

«It’s in the script,» Britton said.

Be that as it may, Oakland resident Gwyneth Iredale said nobody read any such script to her husband when he recently signed up for the JustCall long- distance plan.

«If he had heard 21 cents a minute, he would have stopped right there,» she said. «He doesn’t remember anyone saying that at all.»

Iredale, a telemarketer who works out of her home, said she didn’t learn about the possible penalty for dropping SBC’s local service until the company sent her a letter confirming that her household had joined JustCall.

«It’s like a bait and switch,» she said. «They make an offer that sounds good, but they don’t tell you about the penalty if you don’t meet their requirements.»

SBC’s Britton insisted that the argument is moot because no one would drop their local service for a rival offering but stick with SBC for long- distance.

«Theoretically it could happen,» he said. «But in reality, nobody would do it. You’d switch all your services or none at all. That’s how the industry works.»

Not so, countered Iredale. As someone with a home office, she said she switches calling plans all the time. «There are upstart local services,» she observed. «We’ll take the one that offers the best rate.»

As for SBC’s National Connections plan, Britton said the company has indeed seen some customers failing to meet its requirements.

For example, the plan does not permit people to use their unlimited long- distance service to access Internet dial-up numbers outside their area codes. It also does not allow the service to be used for business purposes.

«It’s intended for residential voice use only,» Britton said. «We especially don’t want people to use it to access the Internet in other places if they’re getting a busy signal locally or can find a faster connection somewhere else.

»We know how long calls last," he added. «If someone is on a call for five or six hours, we can check it out and see if it’s an Internet call. If so, we would follow up on that.»

In such cases, Britton said SBC sends the customer a letter asking that he or she get in touch. «If there’s no response,» he said, «that’s when we would switch to the more expensive plan.»

SBC calls its 21-cents-a-minute service the Simply Talk plan. Yet if you visit the company’s Web site, there’s no mention of Simply Talk, even though it’s the default for most long-distance customers who fall short of other domestic plans.

«The Web site is organized around the most popular plans,» Britton explained. «A lot of our plans aren’t there.»

That would be too easy.

A few million more: I wrote last week how Bob Glynn, chairman of formerly bankrupt utility PG&E, was handed another $1.7 million bonus this month -- on top of $17 million in bonus money received in January.

Apparently that windfall wasn’t enough to tide him over. Glynn recently exercised more than 1 million stock options, providing an additional $6.4 million in ready cash (and bringing his total earnings so far this year to more than $25 million).

«It was a personal decision to diversify his investments,» PG&E spokesman Brian Hertzog said of Glynn’s hefty stock sale last month. «It’s as simple as that.»

No doubt. Yet rank-and-filers at Pacific Gas and Electric Co. tell me that the hot rumor making the rounds is that Glynn, 61, may be on the way out. He’s now exercising stock options he’s held for years.

Hertzog observed that Glynn still holds about 1.6 million options, so investors shouldn’t take his sell-off of 1 million shares as a sign that the boss is worried about PG&E’s future.

As for the rumor that Glynn soon may be vacating his chair in the executive suite -- PG&E CEO Gordon Smith may also be heading toward the exit, some say -- Hertzog said he hasn’t heard anything to this effect.

«There has been no announcement,» he said.

Which isn’t exactly a denial.