I think that the most likely problem here is the driver/software of the webcam, which is the acer crystal eye webcam. You should just uninstall the software from Add/Remove Program (Windows XP) or Programs and Features (Windows Vista).
Then afterwards, reinstall the software/drivers using the disc that came with your Acer laptop, it should contain the all the drivers for the laptop including the webcam. Just pick the correct driver to install. Now if you don't have the CD or is missing you can goto this link: http://www.acerpanam.com/flex/acer/bin/acer.html#app=2766&9e7c-selectedIndex=0&3386-selectedIndex=2&bca4-selectedIndex=1&bf37-selectedIndex=1&4f90-selectedIndex=1
When you open the page by default it should show the Drivers tab. Under the tab there are items you can choose from: Select Product Type, Select Product and Select Download. You first need to click on the "Select a Product Type" choose there Notebook. Then it will goto the next item which is "Select Product" choose there the model of your laptop which is an Aspire 4530. Then it will automatically goto the "Select Download" and it will show all the possible drivers you can download including the webcam drivers (acer crystal eye webcam) and they are labeled either for Windows XP or Windows Vista. So pick the one you need.
Hope this helps!