I have a Yahoo e-mail account, and I am using Opera 8.5 browser. Every time I visit this e-mail account, it takes several minutes to load every page when Avast 4.6 is running. Without Avast running, all the pages loads as fast they normally should do.
What can I do to get the pages to load faster?
Welcome to the forums, cavatina. 
I do not use the Opera browser but there are people on this forum that do. Nor do I Yahoo but there are those here that do. It may be a combination of things not set right.
Hopefully, those who use these will post some help for you soon.
Latest Opera here, and no problems at all. Maybe your ISP is having some kind of problems at the moment. For eg. my ISP had a big problem yesterday and I had only about 1-4 KB/s of usual 30 KB/s bandwitch.
Since =YLAP= has no problems with the latest Opera browser, perhaps Yahoo was very busy or experiencing other problems.
Has this been going on for a few days or was it just the day you posted? ???
This has been a problem for almost two months now.
I have ADSL, and today the bandwith is 1772 kbit/s, so I don’t think this is the reason.