1)  Some problems are on the website twice because it appears in a division 2 contest and a division 1 contest (like 127C is the same as 126A).  I found by accident that if I submit a correct answer to 126A then I can still submit an answer for 127C, and the website will treat this as my total number of problems solved increasing by 2.

2) Also the standings by problems submitted is sorted in alphabetical order after the same number of problems have been solved.  This makes no sense because if I have solved the same number of problems as someone else whose username comes lexicographically before mine, there is no reason for him to be ranked higher in problem standings.