My multiclass elf FIghter Thief keeps losing HP, he was at 75 when I imported him, he is down to 49 and falling. Any idea how to fix this short of reimporting him?

From which game into which game did you import ?
How does he loose HP ?
Are other stats like con affected ?

Does restoration at a temple help ?

Did you equip Ioun Stone or Girdle in CoAB? Those items are bugged, especially if used with imported characters.
I had a similar problem and had to resort to hex editing, or using the Gold Box Companion (editor).

You can use the following trick along with a hex editor to get your HP back to what it should be:

1. Hex edit experience to the value that new characters get. (This needs to be exact.)
2. Use the Modify Character option to change the character;s HP. (This works only because your XP is the same as what a new character would have.)
3. Hex edit your XP back to its previous value.

You can also fix other bugs involving your stats with this method. The advantage over just hex editing your stats is that it enforces the legal range for your stats. (Of note, you might consider temporarily making your female characters male so that you can ignore the sexist limits on female strength, and then changing the character's gender back. Just don't change it to something else if you are playing through the game seriously.)

Thanks for the answers. I found the culprit from them, it was the Belt of the Dwarves. I just deleted and reimported, only lost 25K xp or so, but got the HP back right and will remember to stay away from belts and gauntlets. No worries on the female character, my female Magic User has 18 00 str as she was wearing Gauntlets of Ogre Power when I imported her from Pool.

Yup, there are unfortunately certain glitches with characters that have been imported from Pool :(

One is the Exceptional Strength glitch (character with same gets subjected to STR altering effect, their Exceptional Strength overwrites their original STR score permanently). Another is this particular glitch, and a third is the beneficial glitch of ability buffs making it through the Pool-Curse and Curse-Secret transitions even though they should not given the fact that you lose the gear that provided them.

The reasons for the first and third, I understand pretty well:

* Your character file contains 2 complete sets of ability scores, your current ones and your base ones (so the game knows what to reset your abilities to when an effect is removed, or in the case of Pools, Treasures, FRUA, and Dark Queen, when you choose the Repair option at a temple).

* The third glitch occurs because the game appears to simply copy your scores verbatim instead of accounting for the loss of gear (although how it would account for the loss of items that may or may not be implemented at all in the target game, and even if they are might not have the same binary data records, is hard to imagine, and Curse and Secret both suffer a steady LOSS in magical item diversity, apparently because of the need to implement the new spell levels and the fact that the games were released on some very limited RAM platforms such as C64). It can really only be fixed (assuming you don't want to take advantage of it) once you reach the final game of a series and use the Repair option at a temple (which will reset any altered ability scores that have no associated magical effect back to base ... interestingly, this also restores any CON points that were lost previously to Raise Dead!).

* The first glitch appears to happen simply because the four bytes involving STR (current-STR, base-STR, current-exceptional-STR, base-exceptional-STR) are imported in the wrong order. A simple hex edit corrects this and the problem does not recur for that character.

* The second glitch however, I have no idea why this would behave differently for imported characters ...