Please read this description (you can also see it in contextual help by leaving mouse over the green question mark in yellow field near "Original Odds" in My Bets section and elsewhere):
When you go to Settings (in the upper right corner of every page) or click on [set columns] in the My Bets section you can easily choose to show Odds, Original Odds or both in the table in My Bets.The "original odds" of the slip are the odds based solely on the odds originally entered for each pick. In vast majority of cases the "original odds" are the same as the actual odds of the slip (which we simply call "odds"). The "odds" can differ in case there is a voided pick, a half won asian handicap or a half lost asian handicap on the slip.
There is also usually a difference between the values of these two odds on system slips. The "odds" column shows the adjusted odds of the slip which are actually lowered with every lost, voided, half won or half lost pick. The "original odds" column always shows the odds that were possible with the originally entered odds in case all the picks on the system slip would win. This means that when you cannot win anything from the system, the "odds" column will show 0. When all the picks on the system are either winning or unsettled, the "odds" and "original odds" will show the same value.
You can see both Odds and Original Odds on individual slip pages (where you get after clicking on an ID of a slip).