This is really not an IC2 issue. I know the issue you talk of very well and it's a memory issue related to Minecraft/Java.
Basically, what's going on is this. Minecraft has used up all it's available resources and is now trying to cache on your hard drive. When it starts "freezing", pop open task manager and notice the memory javaw.exe is taking up (assuming you're using windows) It's probably around 1800mb at this point. You will also notice your pagefile is growing like mad man. Services.exe will also start spiking CPU.
It doesn't matter how much system memory you have, Java doesn't seem to care too much about that unless you setup your memory allowances in Java. Also check your system logs after the freezing issues occur, you will notice (if you have nVIdia anyway) that it will be reporting OpenGL memory allocation issues.
I know you may be thinking that you haven't had this issue BEFORE installing the mod or maybe even the updated mod. IT doesn't really matter. Using mods, especially with the new Forge ModLoader seems to allocate a lot more memory than before. Not everyone is going to experience this issue. But if you are running a slightly lower end PC, don't have Java setup to work with over 2GIG ram, and you are running a budget video card (with less than 2GIG VRAM), this issue will creep up once in a blue moon. Closing minecraft and restarting it will ALWAYS clear the issue up because your memory dumps.
I would love to check that, but since it's a random issue i can't take values until the issue occurs, but for what i know java won't let you pass the program memory limit (1024MB by default i think) so that would simply crash with an out of memory exception.
Paging memory to disk shouldn't freeze the game like 10 seconds but slow it down, wouldn't the problem would spread across every app running on the system (as the OS is busy moving programs from and to main memory)?
In any case, if you're right, that doesn't say anything good about forge programming...
Btw, in idle the game stays between 150~300 MB of memory, so where should that difference (from 1800MB) come from?
By now i'll try using 64bit java and setting stack size and heap size to 1GB and see what happens, but i don't think this is a memory issue.