When the Census Bureau scrapped the plan handheld devices for this year’s national census many people thought the Census Bureau’s technological troubles were largely over.

Not so.

The 2010 count now faces different technological problems, two government investigators told Congress Tuesday. Commerce Department Inspector General Todd Zinser and Robert Goldenkoff, director of strategic issues with the Government Accountability Office, said flaws within key software and hardware systems could screw up the count.

The main problem: a software system that manages the maps and workloads for census takers nationwide. It also provides data on households that haven’t responded to the mail-in survey, and helps organize follow-up visits to count residents.

“The testing of the system is continuing to reveal critical defects,” Zinser testified yesterday, warning that possible solutions must be tested and implemented in a hurry if the bureau doesn’t want to spend more than the projected $14.7 billion total cost of the census.

Census Director Robert Groves acknowledged as much, saying that “The performance of this system is not taking the load we’d like. It’s not going to accept the load that we will need to get it in about a month or so.” The census forms will be mailed to each household in the U.S. beginning next month.

Already, the bureau shelled out an extra $88 million for another IT goof: a payroll software glitch that led to $300 payments each to thousands of temporary hires who performed little or no work.

Goldenkoff, who last year rated the 2010 count as “high risk” after the failure of the handheld devices, said that at this point, the bureau’s readiness for a successful count is “mixed.”