[vdr] vdr-1.3.17 bails out when replay stops and a timer active / cutting errors

[Laz <laz@club-burniston.co.uk>]

I think I've finally worked out when this happens:

If I am replaying a recording and a timer starts recording, vdr-1.3.17 
restarts when I stop the replay. Replays are fine when a timer isn't active.

I also noticed another problem when trying to cut a recording with the same 
versions (may have happened with 1.3.16 as well because I haven't edited any 
recordings for a few weeks!). When I start the cut, I get lots and lots of

ERROR: invalid Count in cRingBufferLinear::Del:
13460 (limited to 0)

errors, the live TV goes all stuttery, and it eventually restarts. I _think_ I 
was also seeing these errors as soon as I started vdr when I tested using 
NPTL with this version...

I have just tested NPTL again and I am no longer seeing these errors as soon 
as I start vdr! However, I am now using the thread.[ch] files from 
cadsoft.de, whereas the original NPTL test was with the versions from 1.3.17.

Neither set of thread.[ch] made a difference to the cutting or the "timer 
active when replay stops" errors! Just about to test with thread.[ch] from 
1.3.16...

Cheers,

Laz