W7 Home Premium - Can't open chat and CPU kept 25% on spark.exe

I am using Windows 7 Home Premium 64-bit, spark, i3-M380, 2GB RAM.

Every time I double click/Open a chat via right click a contact, the CPU usage shoot up to 25%, and Spark client is not responding. No chat window appear even I waited for long time.

Any help?

Not without details. Can you look in the debugger of Spark and report the packeages send to the server after double clicking the contact? What’s in the error log? What’s your server in the backend?

As a quick idea: Rename the Spark profile to Spark.old and create a fresh profile.