My Passport 320GB acting strange

Im having some problems with my External HD.
For some reason it will intermittently disconnect & then reconnect to my system, add to that if I save anything to it, the process takes a age even with small files.Theres only about 20gb of stuff saved on it
Is there a fix for this or is my hard drive dieing

We need little more details on your problem. Can you explain intermittent disconnection? Is it  disconnecting from USB? If this is the case, you should hear bells on USB reconnect prompts. Most of the new drives are equipped with power saving schemes and spin down spindle motor to save power. It will take 6 to 10 seconds to before drive become ready, when access it. During this period system may become unresponsive and this is normal.

If drive taking unusually long time (e.g. 5 min for 1MB file) to copy or read  indicates corruption on file system. Most of the time this kind of issues can be rectified by using third party recovery utility and sometimes it needs to be repartitioned and formatted. Drives formatted with FAT32 over a logical drive could get corrupted very easily. Reformatting with NTFS will clear this issue. Lastly this could be an indication of failing drive. Needs more investigation on drive before reaching any conclusion.