In a company I have installed 3 .net Applications. 2 use windows forms, one uses WPF. A couple of weeks ago, some users begun to complain that the 2 win-forms based applications periodicaly hang for several seconds. This can happen on opening menu-items, expanding tree-views, open new windows. During this time, neither network, nor harddisk-operations take place. The CPU's is not busy.
Was there a service pack in the last weeks that may cause .net win-forms applications to react like this? Or has someone another idea or experience? Maybe the antivirus-solution. The AV is MC'Affee, the OS is is windows XP.
The applications were not changed in the last time and they run already for several years without any complaint.