The Fulton County assessors office worked to fix another computer glitch Friday, this one involving missing records that hamstrung residents trying to lower their taxes.

Several homeowners complained that, when looking up parcels through the Board of Assessors' online property records search, not all of the houses on their streets showed up. Two residents who contacted The Atlanta Journal-Constitution said the website has been omitting addresses for the past two weeks.

It caused problems for Donald Perry, who is trying to appeal the county's $379,300 assessment of his Johns Creek home, which he believes is really worth about $313,000. His own home on Mount Oglethorpe Trail came up in a search, which showed only six others.

There are more than 20 houses on his street, and he needs their square footage and taxable values to see if his value is out of line, Perry said.

"I don't think they're doing it deliberately," Perry said. "I think it's more incompetence again. But they're not doing anything to correct it."

Contacted by the AJC, Chief Appraiser Burt Manning said he wasn't aware of the problem until Friday.

"Apparently, when we overlaid the 2011 information, we must have missed some data," he said.

County spokeswoman Jessica Corbitt-Dominguez said in an e-mail that some files didn't upload properly, but the problem was fixed late Friday. By the end of the day, a search of Mount Oglethorpe Trail turned up 21 addresses. Staffers were still verifying that no other data is missing, Corbitt-Dominguez said.

The assessors office came under fire this month when about 136,000 Atlanta property owners received assessment notices with grossly inflated estimates of 2011 tax bills, likely the result of a formula error that factored in solid waste charges multiple times.

The assessors board opted to spend about $140,000 remailing 70 percent of the notices, not only to Atlantans, but also to nine cities whose notices didn't include estimates of municipal taxes. Only Sandy Springs, Johns Creek, Chattahoochee Hills, Mountain Park and unincorporated south Fulton will not receive new notices with a new appeal deadline.