Door Closing Woes...

Hello all.

So it's been a while since I've posted here. There's been three g's in my life since the last post.  All pretty much trouble free, or at least fixable with the knowledge I gleaned in the first rebuild... anyway.. ive currently got a 2003 290gdt (461).  Now im very familiar with how much force one should have to close a g door with, and yes i did replace all the seals on this car recently... however the problem has pre-dated the door seal replacement... (which for the record did neither improver or exacerbate the issue) .. randomly and frequently the doors (all pf them suffer this, but the front two are worst) will just require a disproportionate amount of force to close. They go onto the first part of the latch but struggle to go all the way   Sometimes they close perfectly as one would expect  but others one requires the force of thor.... they are well lubricated   Any ideas?

Thanks  giles