‘Tis the season when dot-com companies should be cashing in. Instead, many in L.A. are scrambling to fill orders and shore up dwindling inventory to meet holiday deadlines.

The situation has annoyed lots of customers and threatened to sour them on online shopping.

“I just went online last week trying to find the Jessie doll (from ‘Toy Story 2’) and couldn’t find it anywhere,” said Reseda resident Karen Garvin, a first-time holiday Internet shopper. “I went to Toys ‘R’ Us, Toysmart and Kbkids.com, and they didn’t have what I wanted.”

Net enthusiast Susan Bohan, who shopped online last year for gifts, said she had a disappointing experience with toy seller Kbkids.com. She couldn’t get on the site, but a message popped up prompting her to click onto a link to receive an e-mail with a discount coupon.

“I didn’t want a discount. I wanted my gift. I didn’t want to wait. I wanted instant gratification,” said the 33-year-old Manhattan Beach resident.

Last week, Santa Monica-based eToys had already posted a disclaimer on its Web site saying it couldn’t promise delivery by Christmas. Ken Ross, a spokesman for eToys, said the firm had increased its Commerce warehouse space fivefold from 100,000 square feet to 500,000 square feet, with other facilities in Utah and Minnesota. Next year, another 400,000-square-foot location will open in Virginia.

“We’ve had an enormous volume of orders, and we expected an enormous volume of orders. We haven’t been perfect. We haven’t been satisfied, and we’re working ’round the clock to that end,” Ross said.

With many of the e-tailers now in their second or third holiday season, some analysts find the level of confusion difficult to figure out.

“I have a hard time believing that somebody is surprised that they’re doing an incredible business this holiday season,” said Ken Cassar, an analyst at Jupiter Communications. “They had to be living in a cave if they didn’t realize sales would be big.”

The volume of business has also overwhelmed Santa Monica-based Cooking.com, a two-year-old online seller of gourmet food products and kitchenware.

Donna Bhattia, vice president of marketing, said the company had planned all year for the holiday season, and sales are even stronger than expected.

“We’re getting more items in orders than we had imagined or budgeted for,” she said. “Our average order is 20 to 30 percent higher than we had imagined.”

Online holiday shopping hasn’t been unpleasant for everyone. Sheena Stephens, 26, of Calabasas said all her purchases were in stock and arrived on time.

“I got online on a Saturday morning in my pajamas and cooked breakfast in between shopping at eToys and the Gap,” she said. “I have six nephews and six nieces, so eToys makes it easier by recommending items for different age groups.”

Locally, sites like eStyle.com and Rightstart.com, which sell baby clothes and toys, are offering free shipping and handling to promote themselves.

“We couldn’t be more delighted with our site. We’re averaging $650,000 a week in sales, which is higher than our expectations,” said Rightstart.com Chief Executive Jerry Welch.