@Lubos, as @Rami_Gomaa earlier highlighted the problem is both with Inventory as @shahabb pointed out and with Suspense account.
For Inventory you need to click in the Inventory Tab one-by-one on the Total Cost and in the subsequent screen on the Recalculate button. I agree with @Rami_Gomaa that this is tedious but a must to get the value of Inventory correct.
For Suspense account, if exists, just edit one by one to clear the faulty entries. Often Bank account, Customer or Supplier and in some cases Account are not entered and need correcting.
I try to be positive about the Inventory changes as some create much more clarity about both process and result, the main caveat remains that you now have to keep recalculating manually the inventory values similar to periodic inventory systems while formerly the calculations where automatically done as expected from perpetual inventory systems. I argued this before but without performing frequent recalculations the important net Profit (Loss) and Equity figures are unreliable in both Summary screen and the related reports. For those having lots of inventory transactions in a day this is worrisome to put it mildly.