Somewhere along the line in GP10, the prior behavior of account lookups (where you type in the first few digits of the account, click the lookup button and it takes you to the beginning of the range) went wacky such that the lookup takes you to the very beginning of the chart of accounts.
If you're experiencing this, here's how to fix it.
1. Open any window that has an account lookup in it.
2. Type a few digits of an account
3. Click on the looking glass
4. Change the default lookup to 'by Account'
5. Select an account
* click image to enlarge
The next time you use account lookup, it will take you to the beginning of the range based on the digits you enter. You need do this only in one lookup window. The change in lookups applies to all account lookups system-wide.