Format of options file

[RS]

Is the format of the options file different in Windows and Linux?  I am 
setting up my machines to dual boot between Windows 10 and ubuntu 16.04. 
  On my main machine I wanted to copy the history file.  I thought while 
I was doing that I might as well copy the whole hidden .get_iplayer 
directory including the cache and options files. I expected to have to 
change the --output option since the path is different, but some of the 
options don't work, and others do.

The criterion seems to be that options with a numeric or boolean value 
like --subtitles or --expiry work.

Options with a string value like --tvmode, --radiomode or 
--ffmpegloglevel don't.  For example with --tvmode=hlshd I get

INFO: Downloading tv: 'Collateral: Series 1 - 2. Episode 2 (b09sym6m) 
[original]'
) available for this programme with version 'original'
INFO: Available modes: 
hlshd,hlsvhigh,hvfhd,hvfsd,hvfxsd,hvfhigh,hvfxhigh,hvfstd,hvflow

When I re-enter --prefs-add --tvmode=hlshd
--ffmpeg-loglevel=info gives an error

INFO: Downloading tv: 'Collateral: Series 1 - 2. Episode 2 (b09sym6m) 
[original]'
') - using defaultalue for --ffmpeg-loglevel ('info

If I enter the options again with --prefs-add they work correctly, so it 
is no big deal.  Any ideas what is happening?