In my experience such card recognition problems have mostly been due to hardware issues, including such things as low contact pressure in the female slot connector (good connection if MC PCB is normally thick, but bad if it is thinner than usual) or simply normal dirt and grease on the metal 'tongues' etched in the MC PCB, or a combination of such things.
And I have not noticed any variation in such problems between recent uLE revisions.
The ability to rename on MC is due to the use of jimmikaelkael's MC drivers instead of the Sony MC drivers in the bios ROM. But recent feedback has shown that the homebrew drivers are faulty for some cases, including inability to work properly with the oldest console models, which is why we have reverted to the Sony driver for v4.40i.i insist on using 4.40g and not the newest version because it lacks the rename on MC support, which i use quite often. i doubt it, but could this issue have been fixed in the latest 4.40i release?
If there is a software cause of the MC problems you have with v4.40g, then there is every reason to believe that it will be different with v4.40i, using entirely different MC drivers. But that will inevitably eliminate the ability to rename on MC, since Sony's drivers do not allow that.
My hope is that jimmikaelkael will have time a bit later to again improve his MC drivers, to gain compatibility with the oldest PS2 model and eliminate any other compatibility issues, at which time we will definitely reinstate those drivers for uLE use.
Until then we have no choice but to use the Sony drivers, as uLE MUST be compatible to all PS2 models. That is not subject to discussion.
But that is no hindrance from keeping a copy of v4.40g around, for those cases where real renaming on the MC is the only practical solution to a problem, while still using the newer release for all other jobs.
Best regards: dlanor