Azure Cache Preview - Premature expiry
===

We're running Azure Cache (Preview) in co-located mode and we've been noticing that sometimes items can not be found in the cache or expires prematurely.

To understand my problem better have a look at the following output from our logs

    2012-07-26 03:14:15,093 [13] DEBUG XXX.CacheBase - Update: XXX-CacheKey-XXX | Abs Exp: 07/26/2012 04:15:15 +00:00 | Sli Exp: 00:00:00
    2012-07-26 03:14:17,452 [22] DEBUG XXX.CacheBase - PessimisticFetch - XXX-CacheKey-XXX
    2012-07-26 03:24:32,229 [23] DEBUG XXX.CacheBase - PessimisticFetch - XXX-CacheKey-XXX
    2012-07-26 03:24:32,245 [23] DEBUG XXX.SomeClass - Item not found in cache: XXX-Cache-XXX 

Explination:

Line 1: Insert into cache with absolute expiry, notice the absolute ex

Line 2: Minute or so later a fetch - A OK

Line 3: 10 Minute's or so later a fetch - Not Found

Line 4: Item reported not found in cache

In short we use GetAndLock / PutAndLock to store these specific items. These items have an absolute expiry (1 Hour) but anything from 5 -- 10 minutes later the item is not in the cache any more.

What is more disturbing on my CacheItemPolicy I've setup a remove notification, but this never gets triggerd

    //---
    cacheItemPolicy.RemovedCallback = ItemRemoved;
    //---    
    
    static void ItemRemoved(CacheEntryRemovedArguments args)
    {
        _log.DebugFormat("Item evicted from cache: {0}. Reason: {1}", args.CacheItem.Key, args.RemovedReason);
    }

I also attached screen shot of our cache setup 
See Image -> http://i.stack.imgur.com/4ORQQ.jpg

I've ran out of ideas what it could be... any leads explanations, WTF's would is appreciated :)