From the Globe:
OTTAWA — Two Conservative staffers have already left jobs working for cabinet ministers to lobby the federal government, despite Prime Minister Stephen Harper's pledge to bar former ministerial staffers from lobbying for five years.
The two, Kevin Macintosh and David Salvatore, left their government jobs this month and started signing up private clients, but the Tories say they broke no rules because they worked as parliamentary aides, rather than ministerial aides, for cabinet members Rob Nicholson and Monte Solberg.
globeandmail.com : Ex-Tory staffers lobby despite Harper's vow
Though Harper promised "to enact strict ethics rules, including a five-year cooling-off period before ministers, ministerial staffers and senior officials can start lobbying the government", this does not apparently apply "to the staff working in a minister's parliamentary office rather than at the department the minister leads."
No word on whether Harper intends to close this loophole.