Seems this problem surfaced after I did the TL door handle swap so I'm presuming its something to do with that somehow.

Anyway, basically my remote stopped working one day, fair enough I thought, bought new battery for remote, paired it with my car using the conventional method. Worked well for 2 days then stopped working again. I know its the remote's problem, as using the key in the door lock will operate the central locking/unlocking. I don't really want to fork out for another battery (expensive suckers for their size).

Anyone else had this problem?

Really common for the soldering to break in the remote itself on the TH on remotes, so its most likely that, every time the solder joins loose connection the battery circuit is incomplete and the remote forgets its memory.

Really common for the soldering to break in the remote itself on the TH on remotes, so its most likely that, every time the solder joins loose connection the battery circuit is incomplete and the remote forgets its memory.

Yeah are the TH remotes the same as my TJ remote? Solder joints looks intact to me

I don't really want to fork out for another battery (expensive suckers for their size).
Really? I got a pack of 5 for less than $10 from eb*y a while back. Are your's CR2032?

I had similar issues with the remotes on my TL caused by dodgy solder contacts between the battery holder and the PCB. The solder contacts LOOKED okay but re-soldering fixed them up.

+1 for Solder, or battery contacts. In one of my remotes, dropping the keys and remote has led to a small fracture in the actual battery holder pin..... its soldered securely to the board but broken part way up, was difficult to spot at first. Going to try to solder it, but my family have burned-out my smallest soldering iron (Murphy's Law at work).

Someone suggested a blob of silastic under the battery case, to absorb shock and take the weight of the battery if keys are dropped. I think that's an excellent suggestion (but suggest using neutral-cure silastic).

Yeah I might replace the fob with the spare key's fob I've just located, will give that a go.. hopefully it hasn't suffered the same fate as my current one.