Web client intermitent hanging

[ThorGoLucky]

The Zimbra web client often hangs while typing messages. It is happening to all users for both IE and Firefox. The hangs can be brief, causing words to have typos of missing letters, and sometimes the hang is so long that it gives error "cannot connect to server". The problem seems to have first appeared after upgrading from version 6 to 7 several weeks ago. Usually a server reboot fixes the problem but not this time. There is plenty of disk space (over 100GB), only half the total memory of 4GB is being used, and both the OS and Zimbra are up to date. Suggestions? If a log should be checked, exactly which one(s)? Thanks!

NE 7.1.2 GA Release
Red Hat Enterprise Linux 4 64-bit

[ThorGoLucky]

The typing delay problem turned out not to be related to Zimbra. It was happening to other web forms but only for Internet Explorer 9. I tried disabling add-ons, clearing all history in case of corruption, and other suggestions to no avail. After some research, it appears that IE simply sux. We have switched to Firefox as our standard browser and all is well now.