Why are the bullets changing on their own?

I’ve created an Impress presentation in which several slides have bullets. The character I’ve used for the bullets is a black right-pointing pointer (OpenSymbol font; Hex U+25BA, Dec. 9658). I changed the color to red and all was well, so I saved the presentation as a .PPT file and continued to work on it as I had time. In case it helps, I’m using LO 7.0.5.2 within W7 SP1.

However, as I’ve continued to work on the presentation, I’ve noticed periodically that on several (but not all) bulleted slides the bullets somehow have been changed to a clock face showing 4 o’clock (Wingdings font; Hex U+F0BA, Dec. 61626). I changed the clock bullet back to the pointer on those slides and saved the file, but when I have subsequently opened the file to work with it, I’ve frequently found that, once again, some (but not all) of the slides with bullets have reverted to the clock bullet. I then tried changing the bullets back to standard, non-bulleted text, re-saved the file, then re-opened it and re-created the pointer bullets on those slides which required them. However, as I’ve continued to work on the presentation, I’ve occasionally found that one or more of the bulleted slides has reverted to the clock face bullets instead of the pointer bullets.

I’m at my wit’s end in trying to fix this problem, as I don’t want to be giving the eventual presentation and find that some of the slides have spontaneously changed to have the inappropriate clock bullets, so I’ll very much appreciate it if someone can come up with an explanation and a solution

Thanks.

so I saved the presentation as a .PPT
file and continued to work on it as I
had time.

Never do it. Always store your important documents in the international standard ODF file formats (.odp for the Impress).
You always will lose some formatting properties when you save your documents into a foreign, obsolete, never standardized file format like the .ppt.

Thank you for your solution. I got into the habit of saving as .PPT because I sometimes presented from other people’s computers which had trouble with .ODP. I will change to .ODP and hope that newer computers will all work well with ODP. Thanks again for your prompt help.

The newer MS Office softwares can open the ODF file formats, but - maybe - they can not open the newest ODF 1.3 version ducuments yet. Use the ODF 1.2 or the ODF 1.1 version. Note the MSO never will able to save into the international standard file formats, because they enforce their semi-closed file formats: the OOXML Transitional (instead of the Strict subversion)
Fortunately every person and company can install the free LibreOffice instead of the expensiv MSO.