I had the same problem so I found this thread. Here is what I ultimately discovered:

Setup/Scenario:

Electrum 1.8x [now upgraded to latest 1.9x]
Used 4 different addresses for different classes of miner payments.

Problem:

Like OP I see transactions on the blockchain which are not referenced in "History".
In my case you can see a balance in a relatively new wallet where no transaction relative to that ID is shown. [see: Receive - Receiving Address/Balance]

Finding:

Like OP I am getting payments from a mining pool. I discovered that multiple payments to my various addresses are wrapped up in a single transaction.

I believe this is a limitation in the display of Electrum, while the balance will be correct the transactions aren't itemized if they fall within a single txid.

Hope this helps!

Well I have been tinkering now for about a week. I was getting a high "apparent" hashrate because I was actually sending bad answers back to the server.

Apparently although the server was discarding them [and not counting toward my earnings] - the sites hashrate for me still included them.

The problem was I hacked together something and was mining with the wrong algorythm. Can also happen if your settings are just way wrong for your card.

Well I have been tinkering now for about a week. I was getting a high "apparent" hashrate because I was actually sending bad answers back to the server.

Apparently although the server was discarding them [and not counting toward my earnings] - the sites hashrate for me still included them.

The problem was I hacked together something and was mining with the wrong algorythm. Can also happen if your settings are just way wrong for your card.

Thanks!

I did some experimental compiling and I am getting numbers on my mining pool page that seem too high to be accurate.

Is this a known issue? I am mining litecoins on a GPU.

My CPU mining operation on another worker is reporting "sane" numbers on the same site.

Thanks!

Hi guys. I just started mining yesterday and I am about 10 minutes from my first Litecoin.

I have a background in Web Development and have been overclocking rigs for years.

Anyway reason I'm posting - my kH/s is a lot higher than I expect for the GPU i'm running. I compiled the s/w myself and tweaked with settings all night, but still the numbers on my pool stats seem high.

Do the sites ever mis-report kH/s values? I have been updating my stats for the last hour and the number is solid. I have another working mining with my CPU and the number it is reporting is sane.

Thanks!!