Reading my textfile as blank

[jskinner]

Here's an excerpt from my code:

void SparseMatrix2D::read(std::string filename) {
	std::ifstream inp, in;
	in.open(filename.c_str(), std::ios::in);
	if(in.is_open()) {
		std::vector<double> cols;
		while(! in.eof() ) {
			char c;
			in.get(c);
			if(c == '\n') {
				matrix.push_back(cols);
				while(cols.size() > 0)
					cols.erase(cols.begin());
			}
			else {
				double d;
				in >> d;
				cols.push_back(d);
			}
		}
		in.clear();
		in.close();
	}
	else {
		std::cout << "file: " << filename << " could not be opened." << std::endl;
	}
}

When I call this function the first time, sure enough it reads in the textfile as I want. The next time I call this function, with a different textfile it only reads in blanks. It doesn't pick up any newlines or anything else.

The textfiles haven't been corrupted or modified in anyway either.

Any help?