#013053: Memcache related tests fail, sometimes

Memcache related test fail sometimes with the following messages. The issue is currently not reproduceable.

1) testPurgeNoLimit(ezcCacheStorageMemcachePlainTest)
Purged IDs not returned correctly.
Failed asserting that two arrays are equal.
--- Expected

Actual

@@ -1,8 +1,3 @@
Array
(
- [0] => ID
- [1] => Some/Dir/ID
- [2] => Some/other/Dir/ID/1
- [3] => Some/other/Dir/ID/2
- [4] => Some/other/Dir/ID/3
)

/home/as/dev/ezcomponents/trunk/Cache/tests/storage_memcache_plain_test.php:530

2) testPurgeLimit(ezcCacheStorageMemcachePlainTest)
Purged IDs not returned correctly.
Failed asserting that two arrays are equal.
--- Expected

Actual

@@ -1,6 +1,3 @@
Array
(
- [0] => ID
- [1] => Some/Dir/ID
- [2] => Some/other/Dir/ID/1
)

/home/as/dev/ezcomponents/trunk/Cache/tests/storage_memcache_plain_test.php:567

This looks like an issue with Memcache itself. However, that has to be determined.

Operating System:
PHP Version: (please be specific, like '4.4.3' or '5.1.5')
Database and version:
Browser (and version):