postage calculator incorrect

[shoppingbag*]

I have been paying for parcels over the counter instead of printing labels, as eBay is still showing the old rates. So I changed all my unsold listings for parcels under 500 grams to the new cost of $7.95, and thought that would fix the problem for those.  After I did this, one item sold and buyer has paid the new postage charge, still ok you would think.  Now when I go to print the label, it says buyer has paid $7.96 (one cent more?) and cost of my label will be $7.60., and no way of changing it.  (I have never received a discount on these, only labels over 500 grams, so I don't think it is a discount)  I didn't set the listing up as a calculated postage, but a set postage of $7.95 which is now the cost and I only charge actual postage.  I really don't know what to do here. I hesitate to go to the local Post Office this time, as I really do think their scales are way out.  Two parcels I just sent were 21 grams and 24 grams more than I weighed them at, (luckily it didn't affect the cost) and I can say with certainty that my scales are only out no more than 2-4 grams maximum on a weighing (increments are 2 grams aand mostly there is only a 0-2 gram error).  I have accurate weights that I test my scales with, and it will also tare weight 500 mls of water at exactly 500 grams. Another Post Office further away had previously weighed one of my parcels only 4 grams different to what I had.  So, looks like I have to go there, what a pain, it's quite a drive.  If anyone can give advice as to get round this any other way, or how to get through to eBay to fix this, then please let me know.  It is a pain not being able to print the labels.  I'm getting so annoyed that I feel like just printing the label as it's presented to me, but I guess that will cause me grief when I go to lodge it at the post office. I presume the price would show when scanned.  Does anyone know if this is the case? Any advice is welcome.