Grants.gov, where federal funding including stimulus money is given out, has announced that the Web site will be down for a "build" this weekend. University officials are furious, according to an official at the Association of American Medical Colleges. The shutdown is scheduled just 9 days before the 27 April deadline for the National Institutes of Health's Challenge Grants, which could attract 10,000 proposals. It's the latest woes for the Web site, which has been straining to keep up with a flood of grant applications from researchers vying for the $8.2 billion in NIH extramural dollars in the economic stimulus bill. To avoid problems, research administrators have been telling their staff members to log on at slower times, such as the middle of the night and weekends. But even this strategy isn't enough, apparently.