Crashes in connection with annotations

Hi

Long ago I reported this bug, however nobody took care of it. Also, the 
bug itself is quite old. It was introduced somewhere around version 
8.5. I investigated the problem a little bit. I found out more than I 
reported last time. I ask myself why no-one else complains about this 
problem. Does nobody use the annotations functionality anymore?

I observe the following:

1. When I load annotations of a page which actually has no annotations 
at all, Amaya crashes with
*** glibc detected *** double free or corruption (!prev): 
0x000000000427d000 ***

2. When I load annotations of a page which has at least one annotation, 
everything works well. But as soon as this page gets cleaned away, 
Amaya crashes with a segmentation fault.
With "cleaned away" I mean the following:
- I close the tab or window
- I enter another URI and laod it in the same tab
- I follow a link and load its target in the same tab
- I close Amaya

I used a debugger to make backtraces for both cases. They are attached, 
bt_1.txt and bt_2.txt

Looking at the backtrace of situation 2, I see that the crash really 
happens while closing a document. I guess that something gets freed 
twice. However, Backtrace 2 does not indicate where to look for the 
problem. But backtrace 1 is interesting. There we find that
RemoteLoad_callback at annotlib/ANNOTevent.c:591 calls TtaFreeMemory. 
This line is:
  TtaFreeMemory (ctx->remoteAnnotIndex);

I simply have commented out this line and looked what happens. And 
indeed, both crashes described above are gone. Of course this might have 
introduced a memory leak ...

I give up at this point. I hope that the Amaya developers will be able 
to eliminate this bug this time.

For the sake of completeness:
I tested it on Debian Linux Etch x86 as well as x86_64.

Greetings
Urs