Hi, Germán;

2012/5/4 Ludovic Courtès <ludo@gnu.org>
Could you apply this patch and confirm?  Alternatively, you can try a

When checking the new patched version of Guile, there is "check-guile" script in root of Guile source directory. After "./configure" and "make", you can execute this script "./check-guile" and it will display many information like this:
  .....
  .....
  Running vlist.test
  Running weaks.test
  Running web-http.test
  Running web-request.test
  Running web-response.test
  Running web-uri.test

  Totals for this test run:
  passes:                 34414
  failures:               2
  unexpected passes:      0
  expected failures:      30
  unresolved test cases:  578
  untested test cases:    1
  unsupported test cases: 9
  errors:                 0

This script write a log file, check-guile.log. In above case, there is 2 failures. you can grep like this:
  $ grep ^FAIL check-guile.log 
  FAIL: gc.test: gc: Lexical vars are collectable
  FAIL: threads.test: mutex-ownership: mutex with owner not retained (bug #27450)

If you find errors, use ^ERROR instead of ^FAIL.