Tonight I had a snipe bid on an item (#390619945162), however I did not win the item although my bid was higher than the winning bid.
In reviewing my bid in myibidder.com, it said: "Seller blocked bidders who purchased too many items from him/her".
However, I have never purchased any items from this seller. Yet in reviewing the seller's feedback, I saw that one buyer had purchased 25 items from this seller about 2 weeks ago.
Is the reason I did not win this item a result of a glitch in the system?
Please note that I am not upset about not winning this item because as you can see, it was an inexpensive item and was not essential to my life or business. I am new to myibidder and I just want to understand why I did not win.
Overall I am delighted that I have found myibidder and have used the program to successfully snipe and win almost 20 items since discovering it about a week ago.

You don't have to purchase anything from the seller for this. Some sellers put a block based on the shipping address where this seller does not ship or other criteria.
This is not a glitch, that's how eBay works by allowing sellers to put certain restrictions which will block bidders who do not meet them.

In the future, when not sure, please place a minimum manual bid first. If your manual bid will not work, your snipe will not work too.
In this case you'll have to contact the seller and ask to either remove the block or add you to the exception list of allowed bidders.

Thanks for your reply. I have sent a message to buyer asking why he/she is blocking me from being able to purchase from them.
By the way I live on the mainland of the U.S.A. (Maryland) and am not someone trying to purchase something with a foreign address. The seller is in Michigan, U.S.A.

There are several rules on how seller may block you.
Funny enough, some sellers may not realize they have a block in place so that's why I highly recommend to verify it by placing a minimum manual bid on important auctions.