I flew paid 1st LHR-FRA-JNB-FRA on LH, though the flights were ticketed as UA flights (e.g., TICKETED as UA #9138 when the flight was actually LH #572, etc.). This was because the flights were ticketed by UA and I flew UA IAD-LHR and FRA-IAD.

I got back to DC Friday afternoon, and checked my mileage balance...

This is what it shows for LHR - FRA:
L# 4737 C Class LHR to FRA 500 625 1125

Base 500, okay, bonus 625 (???) and total 1,125. Seems high to me, almost like it was treated as a UA flight (e.g., 500 minimum miles, 500 bonus for 1K, 125 bonus for business class). And what's "L#" mean? I know it's LH, but that's the nomenclature used.

This is what it shows for FRA - JNB:
L# 0572 F Class FRA to JNB 5248 7872 13120

So the base miles were 5,248, the bonus was 7,872, and the total was 13,120. Why is the bonus 7,872? Isn't it supposed to be only 1.5x miles flown in 1st on LH (meaning the bonus should be 2,624)? This also looks like it was treated as a UA flight. What does "L#" mean in the entry again?

This is what it shows for JNB - FRA:
LH 0573 F Class JNB to FRA 5248 2624 7872

This seems correct to me, and note that "LH" is denoted, not "L#." NOT that I mind extra miles, but why the discrepancy? Was there a promo I missed? Was there a mistake made that gave me extra miles on the way down?

Also note that when I checked in with LH at LHR, it took them almost an hour to do it because it was a United flight (or so I was told). The woman had to run back and forth from the checkin counter to the ticketing counter 4 times (literally), and another agent had to make 3 trips to sort it out (riling the other 1st pax because this was the only desk open for 1st). Do the flight #'s really have something to do with it? This is worrying me because I'm going to be doing these flights with great regularity, and I don't want to have this problem again.

So, to distill my incredibly long questions...

1) Why did I get extra (erroneous?) miles LHR-FRA-JNB?
2) What does "L#" really mean (as opposed to "LH"), and what does that mean to my mileage balance?
3) Do the UA flight #'s always create such havoc on LH, or is this a LHR issue?
4) Can I do anything differently so it won't take an hour to check in at LHR again?

Thanks.

Will