Line breaks in generated csv file driving me crazy

Question

I'm trying to make an export of some data i have (stored in a datatable). Some of those values have a linebreak in them. Now every time i try and import the file in excel (2010), the linbreaks get recognised as a new row, instead of an actual linebreak.

I've searched for hours, seen many solutions, but i just can't seem to get it fixed.

The way i output my csv file: (variable csvfile is a stringbuilder)

context.Response.Clear();
context.Response.ContentType = "text/csv";
context.Response.ContentEncoding = System.Text.Encoding.UTF8;
context.Response.AppendHeader("Content-Disposition", "attachment; filename=" + name + ".csv");
context.Response.Write(csvfile.ToString());
context.Response.End();

When i open it with excel manually, it displays fine. But because excel 2003 doesn't support the file format, i have to import it. With the import, it sees the linebreaks (\n in the fields) as a new row.

Unfortunately i can't give you an example of the real data i work with (it's all personal data), but i can give you an example of how it goes wrong:

Header1,Header2,Header3
"value1","value2","value 3
and this is where its going wrong"

It's a simple csv file, and when you import it you'll see where it goes wrong. I encapsulate fields with double quotationmarks by default. I also remove leading spaces from values by default.

I've spent at least 2 days on this seemingly simple problem, but for the life of me, i can't figure out how i can fix it. I've seen multiple topics on this same problem, but none of the solutions offered there seem to fix this.