The table has a width of 100%, colgroup is set as:
`<col width="1" span="2"> <col>`

Date | text1 | text2
--- | --- | ---
13.06.2010 | bla | blubb

Now, the cols’ width is entered separately, i.e.
`<col width="1"> <col width="1"> <col>`

Date | text1 | text2
--- | --- | ---
13.06.2010 | bla | blubb

Just for comparison, a table without colgroup:

Date | text1 | text2
--- | --- | ---
13.06.2010 | bla | blubb