Tabs disappear from style

I try to define a style for a list in Writer, Build ID: 420m0(Build:2) on Ubuntu. For historical reasons the list should look like this:

  • left indent 10mm
  • each line starts with a paragraph sign (it’s a law text), then some variable space, then a paragraph number (one or two digits, right aligned), some more space, and finally the prargaph title
  • in case the title does not fit one line, it should continue under the title text in the first line, not under the number or even the paragraph sign

I created a paragraph style with a indent before text of 18mm and the first line at -8mm. (Actually these numbers are 17.99 and 8.01mm because for some reason Writer does not like 18mm and -8mm and changes them on its own.)

Then I added tab stops to the style: a right tab stop at 15mm, and a left one at 18mm. When I click “apply” it looks fine. Once I click ok, the dialog closes, and I open it again, the 15mm stop is gone.

Why is that and how can I create a style for this list?
Everything works fine if I just format the item by placing tab stops and modifying the indent in the ruler.

I am unable to reproduce the right tab stop dissappearance using v4.2.8.2 from the website under GNU/Linux. It may be a problem with v4.2.7.2 (although there is nothing in the RC1 and RC2 release notes for v4.2.8 to suggest any related fix) or it may be a problem with the Ubuntu-provided variant.

Thanks. Looks like my LibreOffice is broken; it frequently hangs when modifying styles. I’ll see if I can get a core dump and file a bug report.