RICHMOND, FEB. 25 -- Politics is a funny business, as Emilie F. Miller learned.

Miller, a freshman state senator from Fairfax, decided a few weeks ago she ought to sign on as a member of the Fairfax Chamber of Commerce. After all, Miller considers herself a probusiness Democrat.

So she was surprised last week when the chamber sent a letter, addressed to all 100 members of the state House of Delegates, criticizing one of her bills as "detrimental to the economic interests of Fairfax County and the commonwealth."

The offending legislation proposed to increase the membership of the county's Economic Development Authority from its current level of seven commissioners to 11.

The authority, whose track record at luring new business to Fairfax is impressive, is regarded by many business leaders as a symbol of the corporate community's clout.

Miller thought the bill, which had sponsors from both sides of the aisle, would make room on the commission's all-white roster for a few minority group members and small-business executives. But lobbyists and politicians here said chamber officials had a different interpretation: they thought it was a sneak attack aimed at sacking all seven incumbent commissioners and giving the authority an antigrowth cast, in keeping with the political realignment in the county board elections last fall.

Miller, who sponsored the bill at the request of Fairfax's Board of Supervisors, did not receive a phone call from the chamber or an advance copy of the chamber's letter. By the time she received it, the bill had already sailed through the Senate virtually unnoticed and without opposition, and was headed for the House.

The whole matter, she said, is a giant misunderstanding. But to satisfy the chamber's concerns, she attached an amendment to the bill ensuring that the terms of the seven incumbent commissioners would not be affected.

She still doesn't know if the chamber supports the bill, and chamber officials could not be reached for comment yesterday.

"I don't think they're going to hurt me at all," said Miller, slightly bemused by the events. "They're only going to hurt themselves."

The bill is scheduled for a final vote in the House of Delegates Friday.