pricesUpdated fires in Access ok here. Make sure you have the Beta version which handles event firing better than previous versions. See
http://gruss-software.co.uk/forum/viewtopic.php?t=6477 for download link. Make sure you uninstall the previous version first.
Here is an example Access database with a simple form which demonstrates opening a market, placing a bet, updating and cancelling. Open the TestBets form then click the open market button. When the market has opened the market id appears. Click the place bet button and it will place a lay bet at odds 1.01, stake £2. Click the update bet button and it will update the odds to 1.02. Click the cancel bet button to cancel it.