Certainly, the problem of disappearing Bitcoin is one of those that needs to be addressed before Bitcoin really can go universal.  

I had a multi-coin wallet with 70,000 bitcoin which I send to an exchange.  The wallet showed that the Bitcoin had left the wallet, and the it showed up as a pending deposit in the wallet.  However, the exchange subsequently labeled the address from the incoming wallet "null and void", and removed the value from the pending wallet without adding it as a permanent deposit.  

I went back to the multiple coin wallet, which requires 6 confirmations to send bitcoin, and it showed that there had been -1 confirmations.  At that point I wrote to the wallet saying that since the site acknowledge having -1 acknowlegement, could they return the bitcoin to my balance.  Of course, no answer.

Things like this are kind of common in dealing with Bitcoin.  Perhaps somebody stole my Bitcoin.  More likely, the Bitcoin just ceased to exist.  Unlike a penny dropped in a wishing well, when Bitcoin disappears beneath the surface no physical manifestation remains.  The Bitcoin disappeared with greater ease than any magician could ever demonstrate.

This is just a cost of doing business.  In truth, there is nobody I can go after who will take the time to fix the problem.  If I had used fiat cash, I would not have incurred the problem.  Luckily, I was transacting with myself.  Had I been transacting with someone else, it could well have killed an important business deal.  

It is amazing the crass behavior some of these help desks show.  I was transacting on a site called coin payments, and, again, my bitcoin just disappear in a transaction.  When I asked the help desk to return the bitcoin to the account, the help desk told me that I was a stupid nube, and that I needed to learn a lesson about how bitcoin works.  Obviously, I would recommend that your steer clear of coinpayments.

But nothing is ever stable with Bitcoin.  The company which seems stable today, will turn out to be unstable tomorrow.  For example, the once trusted exchange Cryptsy, is apparently is on the verge of going out of business, and is reportedly not paying out the coins which appear in account balances.  The consumers have a record that the coins exist, but they have no reality in the sense that they can be moved from the site, or transported.

I think the bad attitude you sometimes see from wallet help desks is because the people who are supposed to help you were themselves ripped off countless times, and have become jaded and bitter.  However, overcoming the transient and fragile feel of bitcoin will be necessary if Bitcoin is to show continued long term growth.