Set a breakpoint at a given line number in Adobe's FDB?

Question

I'm learning the Flex command-line debugger, and I haven't been able to find information on this particular use case.

I'd like to add a breakpoint to a specific line in one of my class files. I can add breakpoints at the start of a function in a class, but I can't figure out how to set it at a specific line (e.g. line 117 in Foo.as)?

When I try to set one for a file on a given line, I get one at a different location:

(fdb) break Foo 111

Breakpoint 1 at 0x######: file Foo.as, line 115

I've verified the line # I'm specifying is valid, so I don't think the FDB is trying to compensate.

Am I doing something wrong? Is this possible in FDB?