amenlo9:a lot of thunderstorms around ur area? how about construction?

CRC errors generally are due to the data are changed/damaged/loss en route to ur. maybe due to attenuation or routers error. each data packet has a crc checksum for the router recalculate to see if the data packet received is 100% complete. if its not, it will be discarded. basically there's nothing much u can do about crc error,most of the time the cause is due to the fault of the transmission medium. in other words, ur telephone line (most probably).

interleaved - slower but less error
fast  - fast but might have more error
these are posted somewhere in the forums but i cant recall....

i try to answer the rest of the questions later k...i doing assignment now......hard disk kena bad sector today just got replacement 

this is mine..what a crap
but i never face disconnect problem