Table of Contents Confusion

I'm currently working on a proposal document and I wanted to include a table of contents for the various sections of the document (something that I've done numerous time without any issues).

However, this time for my section headings and sub headings I'm using a numbered list type in the paragraph styles settings so I get automated sequential numbers before each heading and sub heading like so:

1. First section

2. the second section

2.1. a sub section

2.2. another sub section

3. blah blah blah

So far so good, but when I come to generate the TOC the strangest thing happens, it ignores the text after the section numbers. It still outputs the page number reference, but my headings are no where to be seen. So my table of contents looks like this:

1.         page 1

2.         page 2

2.1.      page 5

2.2.      page 6

3.         page 8

Any ideas where I might be going wrong?

Thanks.