That punch list isn't getting any shorter.

Software engineers and tech analysts scrambling to fix HealthCare.gov are discovering new problems by the day, as early fixes take hold and users are able to navigate more deeply into the troubled online application process, administration officials said today.

"We are seeing volume go further down the application. What that means is we are identifying new issues," said Julie Bataille, communications director of the Center for Medicare and Medicaid Services, the agency overseeing the site improvement.

"As volume is exposed to the system, we are identifying new issues, adding them to the punch list and working through them," she told reporters on a daily conference call.

The new complications were described as "capacity issues" and "software issues" within the application and enrollment process, including the steps to determine an applicants eligibility for a subsidy and compare plans.

The latest progress report on repairs to the new federal insurance portal underscores the challenges experts face in trying to meet a Nov. 30 deadline to have the site "optimally functional" - a target laid out by Health and Human Services Secretary Kathleen Sebelius.

Top Obama administration officials have promised Americans that come Dec. 1 the insurance marketplace will be "smooth functioning" for the "vast majority" of users, though they have not offered specific metrics for those goals.

Bataille said today CMS wants improved "page load" times and a sharply reduced "error rate" - two objectives that she says the agency is "on pace" to meet in three weeks' time. However, even as of this morning, the website still exhibited sluggishness in navigation and an inability for some users to simply log-in.

Meanwhile, the Obama administration is keeping a possible extension of the open enrollment period on the table because of the technical problems.

Officials at HHS, CMS and the White House have all told ABC News that they believe there is still plenty of time to get people signed up for coverage by the March 31 enrollment deadline. But none have definitively ruled out an extension of the sign-up window.

This week, several top Democrats and major insurance companies have publicly called on the White House to give people more time.

"We're waiting for guidance from the government around whether they're going to change mandates, [or] whether they're going to do things to extend enrollment periods," said Humana COO Jim Murray on a Wednesday conference call with investors.

"Given where we're at today, our assumption is that there will be an extension to the open enrollment period," he said.